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Targeted public engagement prior to and during the biannual surveys includes:. Over photographs have been submitted to the project of which are approved photographs for the database, based on appropriate metadata, clarity and orientation of the shark. At least, individual sharks have been identified from these photographs comprising sharks identified from both sides plus females and males identified by their right side only. The number of sharks identified by their left side only was slightly less with females and males.

The sex ratio in all photographic categories was almost even. The field methods encourage photographs to be taken of both sides of each grey nurse shark and it is therefore probable that individuals are represented in the database by both their left and right sides. However, it is very difficult to match them as the markings are not identical on both sides. One example of how a shark can be matched to its left and right sides is when features such as dorsal or caudal fin damage have been photographed from both sides during a dive.

GNS Watch faces several challenges. First, considerable time is spent applying for funds and investigating fundraising opportunities to cover costs of the webpage, interactive database, online photo-library, and a program coordinator. Second, it is time consuming to train and retain volunteer project officers to assist with processing the photographs and other behind-the-scenes program outreach.

The consequent delay to disseminating results can lead to disengaged volunteers. Third, poor weather conditions can reduce survey coverage and affect survey timing. Lastly, volunteer divers do not visit some critical grey nurse shark aggregation sites during scheduled survey periods. GNS Watch encourages diving at these sites by offering prizes or relying on research divers or partners such as Sea World, Underwater World, and state government agencies. Despite these challenges GNS Watch has proved to be a successful partnership between researchers and citizen scientists that generates important data for assisting with the recovery of the grey nurse shark along the east coast of Australia.

Citizen science contributions include identifying new grey nurse shark aggregation sites. This information is provided to relevant researchers and management agencies to facilitate further investigation about the importance of aggregation sites to the population. Citizen scientists also report on and provide photos of grey nurse sharks with retained fishing gear and in some instances morbidity is probable without intervention.

GNS Watch liaises with the relevant conservation management agency i. Dolphins and whales cetaceans are iconic marine megafauna that attract considerable public attention. Cetaceans play vital ecological roles as high-order predators and are under pressure from numerous human activities. Species with locally-resident populations that inhabit coastal zones and estuaries adjacent to urbanised centres, such as Moreton Bay, are among the most vulnerable to human activities resulting in pollution, encroachment, boat strikes and other disturbances 24, This includes the Indo-Pacific bottlenose Tursiops aduncus and Australian humpback dolphins Sousa sahulensis.

Cetacean research surveys are expensive and detection rates are typically low, so citizen scientists play a vital role in filling knowledge gaps about population sizes through their sightings This program was initiated in to provide opportunities to engage, connect and empower the public to assist in the conservation of regional dolphin populations and support research efforts.

The program entails: i opportunistic sighting reports from the public; and ii broad-scale land-based observation surveys with trained volunteers. The latter has been established in the Northern Rivers of NSW and during to 16 engaged 15 volunteers in monthly land-based surveys. This is a fee-based program whereby volunteers are trained to participate in hypothesis-driven research during intensive annual surveys. Photo-identification of individuals from opportunistic sightings and dedicated surveys enable estimates of the population abundance, trends and status, along with individual life histories, movement and residency patterns.

As part of the opportunistic sighting reports contributed to Dolphin Watchers, the public are encouraged to report on an online platform the location, behaviour, species and photographs of dolphins observed during their marine-based leisure activities Between and , over opportunistic sighting reports of dolphins from around Australia were received from 34 people through the online reporting platform.

Twenty percent of these sighting reports included photographs and four reports included images for photo-ID. Despite the limitations of opportunistic sighting data of cetaceans for inferring demographic and ecological parameters 39 , there are numerous benefits to collecting these data through citizen science. These include establishing baseline information, identifying previously unknown populations, reporting unusual behaviours, and attaining information about the welfare and health of injured, entrapped or stranded individuals.

Dolphin Watchers promotion has focused on southeast Qld. Although promoting Dolphin Watchers has resulted in a steady stream of opportunistic reports, there have been numerous challenges. The most prominent are: maintaining public engagement and interest; allocating organisation resources including volunteers to handle reports ; funding to continually promote the program; and acquiring quality sighting information including photographs. As human populations and demands on coastal zones increase, pressures from human activities on coastal dolphins are expected to intensify.

Citizen science programs assist in knowledge acquisition and monitoring the status of dolphin populations. Such programs also promote and advocate for environmentally positive behavioural change in participants by providing experiences that can incite a sense of stewardship and meaning to participants. This in turn leads to increased conservation awareness and protection of vulnerable populations such as those in Moreton Bay. Citizen science contributions to photo-ID studies in the Moreton Bay Marine Park have and will continue to contribute to monitoring marine megafauna populations.

However, developing citizen science programs poses several challenges:. Based on the comparative analysis of case studies, there are several recommendations that help to ensure active and effective citizen science programs:. While each species has unique requirements, there are commonalities across the case studies that highlight several benefits of citizen science:. Subscribe to our newsletters:. Your Name required. Your Email required. Subject required. Your Message required.

Volunteer Internship in Marine Conservation and Research

Bennett 1 , Deborah Bowden 1 , Anthony J. Richardson 2 , Kathy A. Search this Paper. Search all Books and Papers. Authors Christine L. Townsend 3 , Elizabeth Hawkins 4. Corresponding author c. Table of Contents. Chapter Chapter 6 Citizen Science. ISBN Abstract Marine megafauna such as cetaceans, elasmobranchs and sea turtles attract considerable public attention.

Keywords : photo-id, reef manta ray, cetacean, bottlenose dolphin, humpback dolphin, grey nurse shark Introduction The Moreton Bay Marine Park MBMP contains diverse and abundant marine megafauna, including marine mammals, elasmobranchs, and sea turtles. Figure 1. Representative photo-ID images of the three case study species.

Orange boxes highlight the areas for identification of the: a reef manta ray, b grey nurse shark, and c Australian humpback dolphin. The project has four main aims: investigating connectivity and movement between populations within Australian and neighbouring waters; estimating population size and variation through time; understanding biological and environmental drivers of population dynamics; and providing management recommendations for populations in the region.

Figure 2. Proportion of reef manta ray Mobula alfredi sightings along the eastern Australian coast contributed by citizen scientists and researchers. Pie chart size represents relative number of contributions at different locations. Citizen scientists contribute photographic records of grey nurse sharks to research projects to address six of the ten objectives of the National Recovery Plan for this species: to monitor numbers of the Australian east coast population of grey nurse shark and determine its trend; to provide information on distribution and movements at different stages of grey nurse shark life history; to provide data to quantify interactions with commercial and recreational fishing gear, along with associated injuries and recovery; to identify new aggregation sites; to increase public awareness; and to provide accurate data for management.

Dolphin Watchers Dolphins and whales cetaceans are iconic marine megafauna that attract considerable public attention. Discussion Citizen science contributions to photo-ID studies in the Moreton Bay Marine Park have and will continue to contribute to monitoring marine megafauna populations. However, developing citizen science programs poses several challenges: Engaging the public and accessing photos.

Each project has to independently develop its online and print-based engagement pathways. Each project has different means of contributing photographs including email, Facebook and directly on USB sticks. Limitations with photo-ID matching. Photographs provide useful data, but can be time consuming and difficult to match.

Automated software options are available, but suffer from false negatives real matches are not identified and are generally unable to cope with wide ranges in photo quality. Volunteers are often sought to assist with photo-ID matching, but considerable training is needed and it can be tedious work that volunteers tire of easily.

Database limitations. Most databases for photo-ID collection are custom made to facilitate the research, but are generally difficult for other researchers or interested parties to access. Maintaining engagement with the public. Engagement is time consuming and the lag between public contributions and the longer-term scientific outcomes makes it challenging to maintain motivated volunteers.

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Long-term funding. While citizen science projects can reduce costs associated with data collection, there are still considerable costs including advertising, training and organising volunteers, online presence, data processing, and disseminating findings through public outlets. A critical role that requires funding across citizen science programs is that of project coordinator.

Traditional scientific funding sources are not always amenable to funding such costs.

Making a Marine Biologist - Ruth Gates Series

Based on the comparative analysis of case studies, there are several recommendations that help to ensure active and effective citizen science programs: Improve networking — create centralized websites, social media outlets and advertising material to enable participants to learn about the suite of citizen science projects and potential contributions. Many citizen scientists have photographs to contribute for more than one target species but may be unaware of the full range of applicable projects.

A central platform for photo-ID projects would produce an economy-of-scale, enabling a greater reach for individual projects to engage new participants cost effectively, as well as disseminate findings. Develop online photo-ID encounter databases — a generic platform could be adapted to specific requirements for each study. Enabling search functions so participants can find their personal sightings would engage the public and help disseminate results. GNS Watch is an example of a project with such an online database, although this was developed at considerable cost, and was not designed with other photo-ID projects in mind.

Create funding consortiums — philanthropic donations of citizen science projects to assist with running costs could be centralized. Centralised consortia could also support and promote long-term industry interactions. While each species has unique requirements, there are commonalities across the case studies that highlight several benefits of citizen science: Increasing research effort. Research surveys only capture a small portion of patchy marine megafauna populations.

Extra data provided by citizen scientists substantially increase data collection and coverage in time and space. Reducing research costs. Boat and scuba diving-based field-work for marine megafauna is expensive. Citizen scientists are self-funded or funded through tourism programs. This substantially reduces data collection costs and also supports local tourism businesses. Increasing public education. Citizen science programs help disseminate research results to participants through continual interaction with researchers. This is also of benefit to researchers, as funding bodies now typically request that results are disseminated more broadly than through specialist journals.

Tangible impacts of research and outcomes. Citizen science programs on marine megafauna in the MBMP have had tangible downstream outcomes for conservation efforts. These programs have engaged a wide-range of stakeholder working groups, as well as informed conservation assessments, recovery plans or zoning reviews. For instance, GNS Watch is a key contributor to the grey nurse shark stakeholder group, who collectively supported the recovery plan review process and wrote to all relevant state and federal ministers providing their recommendations for the conservation management of this critically endangered species.

Trained volunteers and program coordinators distribute and discuss codes of conduct or legislative requirements to field volunteers, tourism operators and more widely to the public outlining behaviour that minimises disturbance to the animals. Photographs have enabled monitoring of sick or injured animals. Our local megafauna citizen science programs also play an important role in engaging citizen scientists and educating the broader community. They deliver numerous talks and distribute updates and educational material online and through other media about the importance of conserving these ecologically and economically important megafauna.

Moreton Bay study: A scientific basis for the Healthy Waterways campaign. Moreton Bay, Queensland, Australia: An example of the co-existence of significant marine mammal populations and large-scale coastal development. Biological Conservation. Taxonomic revision of the humpback dolphins Sousa spp. Marine Mammal Science. An update of the east Australian humpback whale population E1 rate of increase.

Contract No. Santiago June Davie P. Wild guide to Moreton Bay and adjacent coasts 2nd ed. Queensland Museum, Brisbane Taylor S. Population structure and resource partitioning among carcharhiniform sharks in Moreton Bay, southeast Queensland, Australia. The University of Queensland. Distribution, site affinity and regional movements of the manta ray, Manta alfredi Krefft, , along the east coast of Australia.

Marine and Freshwater Research. Seasonality and site fidelity of the zebra shark, Stegostoma fasciatum , in southeast Queensland, Australia. Animal Behaviour. Investigations of grey nurse shark in Queensland to fulfil actions under the recovery plan for grey nurse shark Carcharias taurus in Australia regarding impact of divers, and establishment of a photographic database to improve knowledge of migratory movements, localised site movements and estimation of bycatch.

Department of the Environment and Heritage. Two morphological types of reef occur: structural and unstructural, both showing distinct vertical zonation in terms of species composition and community structure. A comparison of the Baitylong Archipelago reefs with reefs of central and southern Vietnam, Gulf of Thailand and other Pacific reefs reveals an affinity in terms of species composition and reef morphology.

One hundred and forty-two species of Scleractinia belonging to 43 genera were identified, 80 species and 15 genera of which have not hitherto been reported from the Gulf of Tonkin. Introduction The Baitylong Archipelago is located in the north of the Gulf of Tonkin and consists of chains of linearly elongate islands made up of broken carbonaceous, weakly metamorphosed, limestone. As a result of marked erosive processes, they form complex morphostructures with abrasive bays and fiords deeply incising the islands.

The shore is extremely rugged, steeply inclined and filled with debris. The underwater topography is a weakly inclined, aggradative, plain alternating with surface terraces at depths of 6, 9 and 11 m and numerous patches of truncated bedrock. Numerous rivers discharging into the Gulf of Tonkin especially the two large rivers, Thaibinh and Honga transport much suspended organic and mineral material and make coastal waters turbid.

Coral communities over large areas of emergent reefs perish under the freshening effect of the heavy rain. Such physical extremes affect the coral communities. In the western part of the gulf, however, there are the well-known national reserves of Kat'ba Island and Halong Bay about which virtually nothing is known. One study Yet reports that reefs occur here in groups in closed and open bays or in passages between islands. There is one publication on the distribution of coral reefs in the northern Gulf of Tonkin Latypov and Malyutin Data on the coral fauna and the state of reefs lying close to the boundary of the northern tropics will thus be of special interest and this is a study of such communities.

Material and methods A study of coral communities and reef structure was conducted east of Kat'ba Island, the largest of the islands of the Baitylong Archipelago. Distribution of corals was studied on five islands using transect and quadrat techniques Loya and Slobodkin Nine Y Ya Latypov transects with each metre distance marked, were made of the outer and inner sides of the islands, inside straits, bays and fiords in areas of rocky, rubble-covered and sandy coastlines Fig.

The degree of substratum cover by corals, numbers of colonies and density of dominant species were calculated for each transect Maragos and Jokiel Qualitative samples of coral species were collected from each physiographic zone at depths of 1, , and m.

Material and Methods

A total of about samples of coral were collected and species, belonging to 43 genera, were determined. Corals were identified by the author using the following publications Veron and Pichon ,,; Latypov , Small islands and their bays have structureless coral reefs built by settlement of individuals or groups of colonies, rarely by bioherms Fig. Reef deposits form only a veneer; they do not form the reef framework and match the natural profile of the bottom which consists, for the most part, of large pieces of rock rubble and, rarely, of dead coral fragments.

The Fig. B, Map showing the study area and location black circles of the transects. Heet margin Sloping platform m Fig. Reef profile and distribution of abundant macrobenthos on a structural reef Hatched areas limestone reef 29 Y. Latypov Table 1. Species 1. Favia speciosa Dana F. Plesiastrea versipora Lamarck Leptastrea purpurea Dana L. Latypov Lobophyllia corymbosa Forskal L. Pectinia lactuca Pallas P. The reef slope community is divided distinctly into two facies, i.

Towards the base of the reef slope to a depth of between m scleractinian richness and individual numbers decreased. Structural Reefs. The inner reef flat consisted of coralogenic flat cemented crusts and branching colonies of Acropora, Montipora or Pavona and massive heads of Porites, which here formed monospecific strands. Living corals were represented by rare colonies between individuals-nr 2 no more than 10 cm across of massive encrusting forms of Leptastrea, Porites, Platygyra, Galaxea, Pavona, Favia and Favites.

Macrophytic algae occurred among the corals. Between 40 to 50m offshore, the total number of colonies increased to irr 2. Colonies of branched Pavona cactus, Acropora pulchra, Community structure of Vietnamese reefs Acropora millepora and Montipora digitata formed small areas of monospecific settlements and massive P. There were also crusts of Palythoa with areas of up to several square metres and small algal mats of Gracilaria up to 1.

The external reef flat was cut with longitudinal and cross grooves occupied mainly by encrusting and massive colonies between nr 2 of G. Single fungiids, Fungia danai and Sandalolitha robusta, were dominant. The reef slope was steep, with numerous grooves and spurs densely inhabited by different corals. On the upper part of the reef slope, Acropora species, i.

Widespread here were large massive colonies of Porites, Galaxea, Lobophyllia and Favia. Goniopora stokesi occupied areas of hundreds -mr2, and accumulations of Fungiidae, up to m-2, were dominated by Fungia danai. Most widespread were species of Lobophyllia, Symphyllia, Echinophyllia, Turbinaria, Favia, Favites, and Montipora with, as usual for this part of the reef slope, Merulina, Micedium, Pachyseris, Pectinia, Podobacia, and the alcyonarians Sinularia, Sarcophyton, and the gorgonian Ellisella and Antipatharia.

At a depth of between m, only single scleractinian and gorgonian corals occurred. Discussion The reefs on the western part of the Baitylong Archipelago lie at the northern boundary of the distribution of Vietnamese corals and are subject to the strong currents of large and small rivers that discharge silt laden waters, reduce salinity and reduce temperature in winter. In spite of such extreme conditions, the reefs of this region have a relatively high species richness and a high degree of similarity with other Vietnamese reefs and those of the Indo-Pacific Table 1 and Fig.

The reefs studied had More than two-thirds of the coral species are common to the coral faunas of the Gulf of Tonkin and the Gulf of Thailand Dendrogram resulting from clustering of Jaccard similarity coefficients between species compositions of corals in different reefs of the South China Sea. Community structure and species diversity of hermatypic coral at Eilat, Red Sea.

Loya, Y. The Red Sea coral Stylophora pistillata is an r-strategist. Nature Symposium of the Zoological Society of London Maragos, J. Reef corals of Canton Atoll: 2. Local distribution. An environmental survey of Canton Atoll lagoon, Naval Undersea Research. Pichon, M. Dynamics of benthic communities in the coral reefs of Tulear Madagascar ; succession and transformation of the biotopes through reef tract evolution.

Dynamic aspects of coral reef benthic structures and zonation. Porter, J. Autotrophy, heterotrophy and resource partitioning in Caribbean reefbuilding corals. American Naturalist Potts, D. C, Done, T. Dominance of a coral community by the genus Porites Scleractinia. Marine Ecology Progress Series Roberts, H.

Coral reefs of St. Lucia, West Indies. The Caribbean Journal of Sciences Sakai, K. Distribution and community structure of hermatypic corals in the Sichang Islands, inner part of the Gulf of Thailand. Galaxea 5: A. Initial phases in reef development studied at artificial reef types of Eilat Red Sea. Helgolander wissenchaften Meersuntersuchungen 3: Sheppard, C. Interspecific aggression between reef corals with reference to their distribution. Marine Ecology Progress Series 1: Coral populations on the reef slopes and their major controls.

Marme Ecology Progress Series 7: Spencer-Davies, P. Reef forms of Addu Atoll, Maldive Islands. Sorokin, Yu. Coral reefs ecosystems. Moskow: Nauka. Coral reefs and associated invertebrate communities mainly molluscan around Mahe, Seychelles. Philosophical Transactions of the Royal Society of London Titlyanov, E.

Vliyanie sveta na raspredelenie skleractinii v sublitorali ostrovov YuzhnoKitaiskogo morya. Biologia Korallovyh rifov : In Russian. Trible, G. A description of the high latitude shallow water coral communities of Miyakejima, Japan. Coral Reefs 4: Scleractinia of Eastern Australia. Families Thamnasteriidae, Astrocoeniidae, Pocilloporidae.

Australian Institute of Marine Science. Monograph Series 1: Family Poritidae. Monograph Series 4: Family Acroporidae. Monograph Series 5: Wainwright, S. Yet, N. Research results of corals and coral reefs in western Tonkin Gulf. Tay Nguyen va Moy Truong Bien 6 : Zhuang, Q. Studia Marina Sinica Abstract Age and growth of Septifer virgatus Wiegmann from six physically contrasting sites on a wave-exposed rocky shore at Cape d'Aguilar, Hong Kong were determined from the pattern of tidally induced microgrowth bands present in the outer nacreous layer of the shell.

These bands exhibit a distinct seasonal pattern in their deposition with groups of widely spaced bands alternating with groups of narrower bands produced during periods of reduced linear growth. Two obvious groups of narrowly spaced bands are deposited annually, one during the winter February to March when seawater temperatures are at their lowest, the other during the summer July to August when mussels are probably subjected to elevated levels of physiological stress.

Maximum growth was recorded amongst low shore and shallow subtidal mussels whilst the slowest growth rate occurred in mussels located in high intertidal pools. The maximum estimated age of S. Significant intersite variations in shell allometry are reported whilst within each population shells become proportionately wider, more elongate and lighter with overall increase in body size. Introduction The evolution of the heteromyarian wedge-shaped shell the typical mussel form associated with the neotenous retention of the byssus Seed ; Morton has enabled mytilid mussels to exploit successfully hard or semi-consolidated substrata in coastal and estuarine environments throughout the world.

Wherever conditions for attachment and growth are favourable, mussels frequently become the dominant space-occupying organisms Seed and Suchanek Mussel beds are characteristically highly productive assemblages Leigh et al. The genus Mytilus is widely distributed throughout the cooler waters of both northern and southern hemispheres Seed and references therein but in tropical and subtropical latitudes is replaced by other zone-forming genera such as Perna and Septifer though Mytilus galloprovincialis Lamarck is now known to have been recently introduced into Hong Kong waters Lee and Morton Unlike their temperate counterparts, however, these warmer-water mussels have generally been much less intensively studied.

Whilst both Perna viridis Linnaeus and Septifer virgatus Wiegmann are widespread throughout the coastal waters of Hong Kong, the local distribution of these two mytilids rarely overlaps. Thus, whereas P. In this paper we present some preliminary data concerning the age structure and growth characteristics of Septifer virgatus populations from several contrasting habitats on a waveexposed shore at the southernmost tip of the Cape d'Aguilar peninsula in Hong Kong.

Photomicrographs of acetate peels of Septifer virgatus shell sections. Growth lines arrowed in the umbo region U. B Growth lines arrowed in the homogeneous nacre layer. Groups of narrowly spaced bands in the outer nacreous layer NL of a subtidal mussel; two distinct groups of bands arrowed are separated by more widely spaced bands. Groups of narrowly spaced tidal growth bands in the outer nacreous shell layer NL. Narrowly spaced growth bands left of figure and a sudden growth disturbance resulting in a prominent cleft in the shell arrowed , P , penostracum. Shell height was negatively allometric with respect to shell length in all six populations.

Regression constants for various combinations of size parameters in Septifer virgatus from Cape d'Aguilar, Hong Kong. The constants b slope and a intercept respectively in the allometric equation. Size frequency distributions of A, high shore sheltered; B, high shore pool and C, low shore exposed populations of Septifer virgatus at Cape d'Aguilar. Asterisks denote mean values of individual size classes, arrow symbols the estimated age yrs determined from microgrowth bands in population sub-samples. Owen distributions, mean population growth rates can be assessed. This, however, is usually possible only when annual recruitment is relatively restricted and where growth rates of individuals within each cohort are fairly uniform Cerrato Where recruitment is temporally more extended and individual growth rates are slower and more variable, as in many mussel populations, size classes may overlap to such an extent that sizefrequency distributions are of limited value for estimating population growth rate Kautsky ; Richardson et al.

Moreover, although such distributions have previously been used to estimate mussel growth Bayne and Worrall ; Rodhouse et al. Morton followed successive cohorts of Septifer virgatus which recruited onto the shore at Cape d'Aguilar and concluded that although this population comprised six size year classes, the majority of individuals within the population probably had a life span of between four and five years.

This broadly supports the findings of an earlier investigation in which Septifer from Victoria Harbour were estimated to be up to six years of age Morton Similarly, in the present investigation, no individuals over six years old were found, strongly suggesting that this could be the normal longevity of Septifer in Hong Kong waters. The absence of old Septifer virgatus, particularly from the high shore populations, stands in marked contrast to previous reports for. Mytilus edulis in temperate waters where many small, slow-growing, individuals at higher tidal levels may live for over 20 years Seed Such temperatures are close to those which induce heat coma It seems likely, therefore, that the unfavourable conditions prevailing in these pools would result in high levels of mortality, especially during summer.

Liu and Morton , however, have shown that mortality of S. Surface growth rings resulting from seasonal changes in shell deposition have previously been used with varying degrees of success to determine the age of mussels Seed and Richardson Although growth rings on the shell surface of Septifer virgatus are well defined, external rings in mytilids are often unreliable indicators of age as they can arise not only from seasonal variations in shell growth, but also from environmental disturbance and physiological state Richardson et al. In the present investigation, the age of individual mussels and, thus, population growth rates, were estimated from microgrowth bands present in the outer nacreous layer.


Radial shell sections revealed a clearly marked annual pattern in the deposition of these tidally induced bands, with two groups of narrowly spaced bands representing periods of reduced linear growth, produced each year. Whilst one of these groups appears to be associated with low sea water temperatures during winter February to March , the other appears to be related to a period of post-reproductive stress aggravated by particularly high temperatures during summer July to August.

Our data are, therefore, wholly consistent with earlier reports that two surface growth rings are deposited annually in S. Although coupling between reproductive activity and periods of reduced shell growth has previously been described for other bivalves, e. Owen Biology Kautsky, N. Growth and size structure in a Baltic Mytilus edulis population. Lee, S. The population dynamics of the green mussel, Perna viridis L. Asian Marine Biology 2: The Hong Kong Mytilidae. Morton and D. Dudgeon , Leigh, E. Wave energy and intertidal productivity. Lintas, C. Spatial variation in the fauna associated with Mytilus edulis on a wave-exposed rocky shore.

Journal of Zoology Lutz, R. Annual growth layers in the shell of Mytilus edulis. Malacological Review The evolution and success of the heteromyarian form in the Mytiloida. Gosling , , Amsterdam: Elsevier. The population dynamics and reproductive cycle of Septifer virgatus Bivalvia: Mytilidae on an exposed rocky shore in Hong Kong.

Journal of Zoology 50 Ong Che, R. Structure and seasonal variations in abundance of the macro-invertebrate community associated with Septifer virgatus Bivalvia: Mytilidae at Cape d'Aguilar, Hong Kong. Asian Marine Biology 9: Peake, J. Temporal variation in species-area curves for invertebrates in clumps of an intertidal mussel. Ecography '. Ramon, M. Population structure and growth of Donax trunculus Bivalvia: Donacidae in the western Mediterranean.

Age determination and shell growth of Chamelea gallina Bivalvia: Veneridae in the western Mediterranean. Rodhouse, P. Food resource, gametogenesis and growth of Mytilus edulis on the shore and in suspended culture: Killary Harbour, Ireland. Richardson, C. An analysis of the microgrowth bands in the shell of the common mussel Mytilus edulis.

Bivalve shells: Chronometers of environmental change. Factors influencing shell growth in Cerastoderma edule. Use of internal growth bands for measuring Age and growth of Septifer individual and population growth rates in Mytilus edulis from offshore production platforms. Seed, R. The ecology of Mytilus edulis L.

Lamellibranchiata on exposed rocky shores. Growth and mortality. Oecologia 3: — The systematics and evolution of Mytilus galloprovincialis Lmk. Battaglia and J. Beardmore , New York: Plenum Press. Shell growth and form in the Bivalvia. In Skeletal Growth of Aquatic Organisms ed.

Rhoads and R. Lutz , Taxonomic and evolutionary relationships within the genus Mytilus. Systematics evolution and distribution of mussels belonging to the genus Mytilus: an overview. American Malacological Bulletin 9: Mytilus growth and its environmental responsiveness. In The Neurobiology of Mytilus edulis ed. Stefano , Manchester: Manchester University Press. Population and community ecology of Mytilus. Gosling , Amsterdam: Elsevier. Suchanek, T. Mussels and their role in structuring rocky shore communities.

In The Ecology of Rocky Coasts ed. Moore and R. Seed , Sevenoaks: Hodder and Stoughton. The shell structure and the mineralogy of the Bivalvia. Introduction: Nuculacae- Trigonacae. Bimonthly benthic sampling at three stations was undertaken from March to January using a Van Veen grab. Species assemblages were segregated by hierarchical classification into three communities, i. The inner bay was characterized as the Sigambra tentaculata - Veremolpa scabra Aglaophamus toloensis community, the outer bay as the Corophium sp.

Dominant species at each station are listed. Species diversity during the sampling period averaged 2. Evenness and species richness averaged 0. Seasonal variations in diversity index were correlated with summer recuitment of some species. Water quality of Tai Tam Bay showed a general improvement in , as compared with , evidenced by the increased species diversity index for the bay as a whole, the lack of inflection in log-normal plots of species abundance and the increased number of low abundance species. The comparatively lower diversity index in the inner bay and the continued dominance of Sigambra tentaculata, an indicator of moderate pollution, however, remain as points of concern for the fragility of the Tai Tam Bay system.

Continued monitoring of the area is recommended and a list of indicator species which occur in the intermediate abundance groups and which could be the focus of monitoring is provided. A collaborative study between The University of Hong Kong and the Environmental Protection Department of the Hong Kong Government was undertaken from February to January which established the baseline environmental status of Tai Tam Bay with regard to water quality and sediment chemistry Lui , the subtidal macrobenthic community Ong Che and Morton and phytoplankton dynamics and R.

Morton productivity Chan et al. The studies found the bay waters to be generally 'clean'. A potential problem of eutrophication was, however, suggested by the lower benthic species diversity indices and higher chlorophyll a values at the innermost bay station. The studies recommended continued monitoring to delineate long-term trends in the area, but at a reduced number of stations, i. This study is a response to that recommendation and reports upon a further twoyear investigation of the subtidal macrobenthic community of Tai Tam Bay. Ecological studies have been undertaken in the area over a period of 15 years and their findings are discussed in an attempt to define overall trends in environmental quality.

Dominant species were also selected by means of the Biological Index of Dominance B. Fager This method determines the relative abundance of the species using rank-score analysis on a 5-point system. In a given sample, the most abundant species was given 5 points, the next most abundant 4 points and so on. Three replicate samples were obtained with a Van Veen grab 0. The locations of the stations are identified in Lui , Fig.

Samples were washed on board through a 0. Sorting procedures were as described in Ong Che and Morton Dominant species Species 54 were ranked according to their N N H' In S InN where Ntis the number of individuals in the i-th species, N the total number of individuals in a sample and S the total number of species. Seasonal variations in diversity indices were examined by plotting them against time for each station.

Community patterns and seasonal differences in species composition were further analysed using agglomerative hierarchical classification. Similarity between station - time groups was calculated using squared Euclidean distances. Clustering utilized the group - average linkage which defines the distance between two clusters as the average of the distances between all pairs of cases in which one member of the pair is also a member of one of the clusters.

Log-normal plots The 'health' of the Tai Tam benthic communities was examined by the method of Gray and Mirza Log-normal plots of the cumulative percent of species in different geometric classes x 2 scale were constructed for inner, middle and outer bay stations, i. Plots were also made using the percentage number of species on the ordinate in order to identify the species in the community which occurred in intermediate numbers and which could serve as potential indicators of pollution Pearson et al. Table 1 shows the percentage distribution of species and individuals among the major taxa at the three stations.

Table 1. Percentage numbers of species A and of individuals B recorded for different faunal groups sampled in - at three stations within Tai Tam Bay. This may be due to the bias arising from high catches of some species in some seasons. The ranking of the five dominant species at Station 1 remained unaltered between the and sampling years on the B. In contrast, community dominants at Station 4 changed between and In , all of the dominant species except one were polychaetes, whereas in , polychaetes comprised only half of the dominant species list.

Community dominants at Station 5 were mostly non-polychaete species. Half of these were amphipods. The change in the dominant taxa between Stations 1, 4 and 5 correlates with a shift in substratum type from mud in the inner bay to sand in the outer. While absolute ranking changed between the two sampling years, the dominant species selected by the two methods remained largely the same. Similar to the observation noted for Station 4, the community recorded at Station 5 comprised many 'rare' species. The five most dominant species at Station 1 were the same in and in Dominance ranking, based on the two methods used, differed, however.

Numerical abundance of Veremolpa scabra decreased from Mean diversity ranged from 2. T - tests comparing diversity indices between years indicate, however, that differences were not significant. Species diversity over the two-year sampling period averaged 2. According to the criteria used by Jhingran et al. Dominant species ranked on the basis of percentage representation in pooled samples and on the Biological Index of Dominance B.

A, ; B, Morton Table 3. T-test results comparing diversity values between years are also presented. The two-year averages of species richness for the outer bay Stations 4 and 5 were 4. Species diversity indices at the outer stations 4 and 5 were consistently higher throughout the year, as compared with the inner station 1. A parallel trend was obtained for species richness, with the highest values being recorded from Station 5 and the lowest from Station 1, throughout the year. Evenness was relatively constant at Station 4, with only a slight decline in September and March In contrast, Stations 1 and 5 showed greater fluctuations.

The reductions in evenness which occurred in summer July to September at these stations were more pronounced in than in Recruitment of some species in summer, e. Counts of V. Relative abundance of Corophium sp. A less pronounced fall in evenness in March at Station 5 resulted from high catches of Hyale sp. Species diversity, as reported in the first study on the Tai Tam benthos Shin , averaged 3. Diversity decreased to 3. A comparison of Species Diversity Indices H of the Tai Tam Bay macrobenthic community reported upon in this and previous studies over a period of 15 years.

Following the criteria specified in Jhingran et al. Hierarchical clustering Results of the hierarchical classification of the - species abundance data are presented in Figure 3. The similarity index on the ordinate axis has been converted to rescaled distance where smaller distances indicate greater similarity.

The present analysis of data obtained from three stations with three replicates each has verified the community patterns defined by the classification of the - faunal data obtained from five stations with five replicates each Ong Che and Morton Stations were segregated cfr. This segregation correlates well with the substratum type occurring at these three sections of the bay, i. Some interspersion of contiguous stations occurs, however, reflecting an overlap in species distributions between stations.

The mid-bay transition community Station 4 showed greater species overlap with the inner bay mud community than with the outer bay sand community. This suggests that the benthic communities of Tai Tam Bay are not strictly delimited and conform to the concept of communities as a continuum of species distributions Gray The presence of such community gradients within the bay is also reflected in the clustering schedule which shows many small increments in distance, that is, clustering of similar groups.

The analysis of station, replication and time month, year groups shows that replicates were representative of the area sampled. The three replicate samples were clustered in consecutive steps in 18 out of the clustering stages while two out of the three replicates were similarly grouped in 30 out of the steps cfr. No strong seasonal differences in species composition were apparent from the classification results. Seasonal cycles in benthic communities 59 R.

Hierarchical agglomerative classification analysis of station - replicate - time months, years groups within Tai Tam Bay. Squared Euclidean distances on the ordinate have been rescaled to fall within the range 1 - Smaller distances indicate greater similarity. In subtropical Hong Kong, water temperatures in three seasons winter, spring and autumn are similar and fall within a narrow range Distinctly higher temperatures occur in summer Thus, in the classification analysis, winter, spring and autumn samples are generally unsorted and species assemblages may only be different between the cooler times of the year and summer cfr.

Log-normal plots Log-normal plots of the cumulative percentage of species in different geometric classes are shown in Figure 4 for the - data from Stations 95 -, 1, 4 and 5. A single, steep, slope was obtained for all the stations in both years. The number of geometric classes was low, ranging from six at Station 4 to a maximum of eight at the other two stations. Figure 5 presents log-normal plots of the number of species against the number of individuals-species-1 in geometric classes for the consolidated faunal data - from Stations 1, 4 and 5 at Tai Tam.

The time series plots show a log series distribution with the majority of the species being represented by one individual-sample-1 geometric class 1. The range of geometric classes decreased from between 8 to 10 in the - sampling period to between 6 to 8 in - , indicating that fewer species in the higher abundance classes were recorded during the second phase of sampling. Log-normal plots of individuals-species-1 sampled in the - survey of three stations 1, 4 and 5 in Tai Tam Bay.

Plots of percentage number of species in different geometric classes for the faunal data obtained from two surveys of Tai Tam Bay in - and - When the lower abundance groups were compared over the two sampling periods, more species were recorded in low numbers geometric classes I to IV in - Similarly, the percentage of species in the intermediate abundance group geometric classes V and VI decreased over the two sampling periods at both Stations 1 and 5, i. This change was even more obvious at Station 4 where no species had a relative abundance greater than 32 individuals-sample-1 geometric class VI in The Tai Tam log-normal plots reflect this situation, especially in The species in abundance classes V and VI are listed in Table 4.

None of these species has been reported to be pollution indicators. Some related species are, however, known to have wide ecological requirements and are indicators of environmental perturbation. Examples of such related species are Chaetozone setosa, Lumbrinereis latreilli and Prionospio malmgreni Food and Agriculture Organization Tai Tam subtidal benthos Table 4. Geometric class V individuals-species-1 Geometric class VI individuals-species-1 Minuspio sp. Pseudopolydora sp.

Veremolpa scabra Minuspio sp. Chaetozone spp. Sigambra tentaculata Aglaophamus toloensis Veremolpa scabra Prionospio saccifera Station 1 Station 4 Mediomastus californiensis Chaetozone spp. Aglaophamus toloensis Ampelisca cyclops Caprella aequilibra Station 5 Campylaspis angularis Corophium sp. Ophiura kinbergi Podocerus sp. Prionospio sp. Golfmgia misakiana Branchiostoma belcheri Ampylaspis angularis Corophium sp.

Colelepis sp. Stenothoe sp. Discussion Community structure Benthic communities have traditionally been characterized by the dominant species occurring in them. According to Petersen who Branchiostoma belcheri Caprella aequilibra undertook the first quantitative study on the marine benthos of Northern Europe, these community-characterizing species should have two traits, that is, either numerical or biomass dominance, and a recurring presence within the community. In their study of the spatial distribution of the 63 R. Morton infaunal benthos of Hong Kong, Shin and Thompson delineated five communities using agglomerative hierarchical classification.

They declined to name these five communities after the three most dominant species, however, because of low fidelity. Several of the dominant species occurred in more than one of the five community groupings. In the present study, low fidelity was also observed, resulting from communities not being delineated by rigid boundaries. A few of the dominant species selected by percentage representation in pooled samples and by their Biological Index of Dominance ranking were recorded from more than one station.

The abundance of these species at the different stations differed, however. Conversely, Stenothoe sp. Brown discussed the relationship between species abundance at different spatial scales and niche size. According to Brown, a species is most abundant at the centre of its niche and decreases in numbers towards the edge. The intergradation of communities within Tai Tam Bay need not, therefore, invalidate characterizing these communities after the dominant species. Communities can be named after the dominant species which occur at the centre of their niches.

The Biological Index of Dominance B. By taking the mean of the B. Station 1, in the inner bay can be characterized as the Sigambra tentaculata - Veremolpa scabra -Aglaophamus toloensis community in the order. Ampelisca cyclops - Mediomastus californiensis community and Station 5, in the outer bay, as the Corophium sp. The communities thus named reflect high fidelity. Although the animal assemblages in these three locations showed intergrading dominance of species, the fidelity of key species in characterizing the particular location was high.

Thus, the urchin Schizaster lacunosus, the ophiuroid Ophiura kinbergi and the venerid bivalve Paphia undulata were confined to Mirs Bay, the polychaetes Prionospio ehlersi and Lagis koreni to Tolo Channel and the polychaetes Sigambra tentaculata, Minuspio cirrifera, Tharyx sp. Of the polychaetes dominant in Tolo Harbour, two are associated with areas of environmental stress. Minuspio cirrifera has been regarded as an indicator species of moderate organic pollution at Oslofjord, Norway, by Mirza and Gray and at Victoria Harbour, Hong Kong, by Thompson and Shin Sigambra tentaculata has also been reported in great numbers in an anoxic basin at Golfo Dulce, Costa Rica by Nichols-Driscoll The presence of these pollution indicator species in Tolo Harbour, together with information from other studies describing environmental deterioration in the area Wong, et al.

In the present study, both Sigambra tentaculata and Minuspio sp. This interesting parallel in the pollution indicating polychaete species occurring at inner Tolo Harbour and inner Tai Tam Bay suggests that the environmental changes which have been affecting the Tolo Harbour infaunal community may be operating at inner Tai Tam Bay as well, albeit at a less intense degree.

Species richness was consistently lower in the inner bay Station 1 compared to the outer bay Station 5 during the two phases of sampling spanning four years. Lui reported temperature stratification of the water column in Tai Tam during the summer months and that this Tai Tam subtidal benthos Table 5. Consolidated dominant species list at Tai Tam Bay. The five most dominant species and the mean B. Ties were given average ranks and species not among the top five that year were given an arbitrary rank for calculation of the mean B.

Morton during this study, Circe Laevicirce hongkongensis sp. The polychaete Prionospio sp. The taxonomic status of many invertebrate species in this total Tai Tam Bay community remains to be clarified. Ecological monitoring The water quality of Tai Tam Bay, as reflected in the data presented here of an overall increase in benthic species diversity, apparently showed a general improvement during the second phase of benthic sampling in Log-normal plots of the cumulative percentage of species in the different geometric classes showed a single steep slope at all stations for both years.

In addition, most of the species occurred in the low abundance groups. These two facts, together with the increased mean species diversity index, are believed to support the notion of improved water conditions in the inlet. The dissolved oxygen profile showed fairly well oxygenated waters with annual mean D. Levels of inorganic nitrogen, organic nitrogen, inorganic phosphate and mean surface chlorophyll a during this period were all below the cut-off criteria for eutrophication, i.

The mean B. Government reports attribute the improved water conditions and the significant reduction in observed red tides to the successful implementation of the livestock waste control scheme in the gazetted water control zone Environmental Protection Department, Hong Kong In a concurrent study of the phytoplankton dynamics of Tai Tam Bay, Chiu et al. At both stations, from July to March , the measured chlorophyll a content of both surface and bottom waters was less than the eutrophication level set by the Environmental Protection Department of the Hong Kong Government, i.

The only substantially higher chlorophyll a level was measured at the last sampling date of their study, i. This was parallelled by the higher ammonium - nitrogen content measured in May which increased beyond the range observed during the early part of their study. No unusual increase in May was obtained for nitratenitrogen and ortho-phosphate content in the study of Chiu et al.

Although Tai Tam Bay waters are considered to have exhibited a general improvement in water quality during this second phase of monitoring, the continued dominance of Sigambra tentaculata, an indicator of moderate pollution Shin and the marginal species diversity index recorded in this study for the inner bay Station 1 remain as points of concern signalling the fragility of the Tai Tam Bay system.

In addition, the high chlorophyll a levels reported upon by Chiu et al. In view of the ecological importance of this site, its close proximity to Cape d'Aguilar, the only proposed marine reserve in Hong Kong and the gazetting of sludge and construction waste dumping sites off southeastern Hong Kong, both of which may affect the marine biota of this site, further long-term monitoring of the area is recommended.

Much of the baseline information on the Tai Tam subtidal macrobenthic community have been collated in this and a previous study Ong Che and Morton These relate to species assemblages, community structure, species numbers and abundance, diversity indices, seasonal patterns and log-normal plots. The present study has demonstrated that the three-station-three-replicate programme yielded results comparable with those obtained in the first study using a five-station-five-replicate protocol.

Morton Patna, Bihar, India. Current Science Jiang J. A new species of Veneridae Bivalvia from Hong Kong waters. Journal of Oceanography of Taiwan Strait Lui, P. Asian Marine Biology Margalef, D. Information theory in biology. General Systems Yearbook Mirza, F.

Asian Marine Biology 10

The fauna of benthic sediments from the organically enriched Oslofjord, Norway. Marine pollution induced changes in Hong Kong — the Tolo Harbour case history. In Pollution in the Urban Environment ed. Chan, R. Hoare, P. Holmes, R. Law and S. Reed , Polmet '85, Hong Kong. Nichols-Driscoll, J. Benthic invertebrate communities in Golfo Dulce, Costa Rica, an anoxic basin. Revista de Biologia Tropical Norusis, M. Pearson, T. Objective selection of sensitive species indicative of pollution-induced changes in benthic communities. Data analysis. Petersen, C. On the animal communities of the sea bottom in the Skagerrak, the Christiania Fjord and the Danish waters.

Report of the Danish Biological Station Shannon's formula as a measure of species diversity : its use and misuse. A quantitative and qualitative survey of the benthic fauna of the territorial waters of Hong Kong. Phil, thesis, The University of Hong Kong. Benthic invertebrate communities in Tolo Harbour and Mirs Bay : a review. Spatial distribution of the infaunal benthos of Hong Kong.

Thompson, G. Sewage pollution and infaunal benthos of Victoria Harbour, Hong Kong. A trawl survey of the benthos of Tolo Harbour and Tolo Channel in Wong, M. A preliminary survey of organic pollution of shellfish in Tolo Harbour, Hong Kong. Hydrobiologia Wu, R. Periodic defaunation and recovery in a subtropical epibenthic community in relation to organic pollution.

Liu1 and L. Lu squamosa suffers heavy predation pressure on the shores of Cape d'Aguilar, Hong Kong Liu, unpublished data. Alternatively, young B. This study examines the occurrence of Balanus amphitrite on a wide variety of molluscan shells at Cape d'Aguilar, Hong Kong, to determine habitat choice between different hosts. Site 1 Materials and methods Two sites were chosen for study. Site 1 was located on the northern shore of Lobster Bay on the westen shore of Cape d'Aguilar and is exposed to moderate wave action.

Sampling areas were located between 0. A, a map of Hong Kong showing the location of Cape d'Aguilar; B, the location of the two study sites at Cape d'Aguilar 70 Balanus amphithrite on the gastropod Thais clavigera lower parts of the shore. Areas of 0. The numbers of individuals of each species. Barnacle settlement on each shell was recorded in terms of either the presence or absence of individuals of Balanus amphitrite.

The numbers of B. This work was undertaken during October The percentage frequency of occurrence of one individual of B. Only one shell from the exposed site hosted 12 individuals of B. Figure 3 shows the relationship between Thais clavigera host size and numbers of attached barnacles.

At site 1, i. At site 2, i. Results Table 1 shows the percentage frequency of each species used as a substratum by Balanus amphitrite from the semi-exposed shore in Lobster Bay at Cape d'Aguilar. The total number of B. Additionally, individuals of Tetraclita squamosa, 29 individuals of Cellana toreuma, individuals of Patelloida saccharina, 2 individuals of Nerita albicilla and 18 individuals of Liolophura japonica were examined, but only 1 individual of C. From the exposed eastern shore at Cape d'Aguilar Table 2 , 47 individuals of T.

Additionally, individuals of T. A narrow range of gastropod species was settled upon by B. The mean shell lengths of B.

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The frequency of occurrence of different numbers of Balanus amphitrite on Thais clavigera hosts are shown in Figure 2. One individual may occur on one host shell but there may also be a Discussion The present work shows that Cape d'Aguilar supports a population of Balanus amphitrite which largely occurs on the shells of the predatory snail Thais clavigera.

Differential settlement means that larvae do not settle randomly but settle instead on specific sites as a result of complicated interactions with environmental factors. Bourget listed 12 environmental factors which have been shown to influence the settlement of intertidal barnacles. These factors include light quality, background illumination, surface angle, surface contour, surface texture, tidal currents, wave action, water depth, shore level, the presence of conspecifics, bacterial film and algae.

Pollicipes larvae do not settle on either etched or smooth glass slides with or without bacterial films. Mapstone et al. This preference is not explained by the relative shell area of A. The percentage frequency of each species used as a substratum by Balanus amphitrite from a semi-exposed shore at Cape d'Aguilar, Hong Kong. Size 14 30 46 60 The percentage frequency of each species used as a substratum by Balanus amphitrite from an exposed shore at Cape d'Aguilar, Hong Kong.

Size Thais clavigera 27 58 47 88 The relationship between host size and numbers of attached individuals of Balanus amphitrite Site 1, semi-exposed shore; Site 2, exposed shore. It may also be that B. These authors all record that limpets reduce the survival of post-settlement barnacles. Petraitis demonstrated that the periwinkle Littorina 74 littorea strongly affects the abundance of the barnacle Balanus balanoides. At high densities, L. Experiments on the larval settlement of B. Settlement of B. Balanus amphitrite is known to form associations with other organisms.

Table 3 Balanus amphithnte on the gastropod Thais clavigera Table 3. Published records of Mollusca-barnacle associations. Gastropod hosts used by other species. Gastropod host Species Reference Batillaria spp. Crepidula walshi limpet-like snail Yipp Calliostoma ligatum Crepidula adunca limpet-like snail Vermeij et al. The molluscan hosts are typically bivalves, e. There is no information available about the settlement of barnacles on gastropod hosts, which are, for example, widely used by other animals, e. We did not investigate the differences between the shells of Thais clavigera and the shells of other gastropods in terms of surface texture, surface contour and bacterial film.

Maki et al showed that bacterial films generally inhibited attachment of larval Balanus amphitrite. We thank Professor Brian Morton, Director, The Swire Institute of Marine Science, The University of Hong Kong, for the provision of laboratory facilities and work space during the course of this study and for his critical reading of the first drafts of the manuscript of this paper.

Lu Barnes, H.