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Appendix 4 - Other species of conservation concern

Whilst not included in the previous two categories of listed threatened or marine species, or species of special interest, these marine species are of conservation concern within the Great Barrier Reef Marine Park (GBRMP).

Landscape format / close-up shot / a Black manta ray with remoras swimming underneath it, in murky waters at Tryon Island

Sharks, Rays and Skates

Knowledge

  • Refer p.132 of The Outstanding Universal Value of the Great Barrier Reef World Heritage Area (Lucas et al. 1997), which notes that ‘specific locations of importance for the fishes of the Great Barrier Reef World Heritage Area are difficult to identify’.
  • Refer p.53 of the State of the Great Barrier Reef World Heritage Area 1998 (Wachenfeld 1998), which notes that ‘information on the state of populations of pelagic fishes is scarce, even for those that are commercially exploited’.
  • From Last and Stevens (1994):
    • Australian species diversity
      • Sharks: 166
      • Rays/Skates: 117
    • More than 50% of Australian sharks and rays are endemic to Australia
    • Long-lived (10-70 years)
    • Late maturing (6-7 years)
    • Low fecundity (2-50 pups)
    • Occupy broad range of habitats, from inshore, shallow waters to depths greater than 2000m
    • Carnivores and scavengers
    • Pogonoski et al. (2002) list 28 sharks and rays in the Great Barrier Reef.
    • Taronga Zoo (NSW) maintains an Australian Shark Attack File that provides up to date facts, statistics and advice about attacks. As of February 2003, there had been 70 fatal attacks recorded since Europeans arrived in Queensland: 9 in the last 20 years, 13 in the last 30 years, 14 in the last 40 years, and 21 in the last 50 years. Statistics at the website show clearly that compared to fatalities from other forms of water activity, the risk from shark attack is very low.

Conservation status

Human Related Threats

  • Defence exercises
  • Fishing, shark control programs (e.g. shark netting) and aquaculture
  • Hunting and collecting
  • Tourism and recreation

Actions

  • The Conservation Overview and Action Plan for Australian Threatened and Potentially Threatened Marine and Estuarine Fishes compiled for Environment Australia (now Department of the Environment and Heritage) by the Australian Museum and NSW Fisheries was finalised in 2000.
  • The World Conservation Union (IUCN) has developed guidelines for applying Red List Criteria to marine fishes.
  • A National Plan of Action for Sharks in Australia was released in May 2004.
  • In March 2003, a regional workshop in Brisbane of the IUCN Shark Specialist Group (SSG) assessed the conservation status of 201 species of Chondrichthyans (156 sharks, 41 batoids and 4 chimaeras) occurring in Australia and Oceania. 14 were classified as threatened using IUCN criteria (4 critically endangered, 1 endangered and 9 vulnerable), 66 as Near Threatened, 84 as Least Concern and 37 as Data Deficient. The results are to be considered by the global SSG before submission to the IUCN Red List. The workshop report is available here.
  • National Recovery Plans have been finalised for Great White shark and the Grey Nurse shark.
  • The GBRMPA routinely liaises with the Queensland Shark Control Program.
  • Conditions in scientific collecting permits prevent the capture of great white, grey nurse, and whale sharks. The Species Conservation Program also recommends to researchers that as few specimens should be collected as possible of species listed as threatened in the Conservation Overview and Action Plan for Australian Threatened and Potentially Threatened Marine and Estuarine Fishes.
  • The GBRMPA’s Fisheries Issues Group liaises with the Queensland Department of Primary Industries and Fisheries and fishers on the sustainability of shark catches in Queensland.
  • The Species Conservation Program works with the Fisheries Issues Group of the GBRMPA to monitor and address concerns regarding fish conservation.

Landscape format / close-up shot / a bright orange, white-banded Clown anemonefish, swims amongst cream coloured anemone tentacles

Other Marine Fishes                

Knowledge

  • Refer p.131-133 of The Outstanding Universal Value of the Great Barrier Reef World Heritage Area (Lucas et al. 1997) which says, ‘there are no Great Barrier Reef World Heritage Area fishes recognised as threatened (Williams, D. 1996, pers. comm.) p.132’.
  • Conservation Overview and Action Plan for Australian Threatened and Potentially Threatened Marine and Estuarine Fishes (Pogonoski et al. 2002) details 114 species of the approximately 4,100 marine and estuarine fish species known to occur in Australian waters. The main causes of declines in marine and estuarine fishes have included overfishing (of both target and non-target or by-catch species), habitat degradation (from urban development and related activities, trawling, dredging, water pollution, etc.), and, to a much lesser extent, exotic species introductions.
  • Several fish species in the Great Barrier Reef are known to form large spawning aggregations, however much remains to be learned about different species aggregation characteristics (Spawning Aggregations Working Group, 2002).
  • Commercial and recreational fishers target reef fish species directly and incidentally on fish spawning aggregation sites (FSAS).
  • Approximately 1500 fish species in the Great Barrier Reef World Heritage Area (GBRWHA).
    • Low endemism as most fish are distributed throughout the Indo-West Pacific region
    • Cross-shelf, temporal and latitudinal variation in species richness: greatest on mid-shelf reefs; lowest on inshore reefs.
    • Abundance and diversity of fishes changes over a range of spatial and temporal scales.
    • Occupy all habitats (benthic, pelagic, hard and soft substrate, mangroves, seagrass beds).
    • Greatest species richness in coral reef habitats, followed by mangrove and estuarine environments.
    • Large and small home ranges.
    • Range of reproductive strategies: broadcast spawners, brooders
    • High fecundity.
    • Range of feeding strategies: planktivores, herbivores, omnivores, carnivores.
    • Migration to near shore or offshore areas for spawning show connectivity between habitats.
  • Refer p.51-56, State of the Great Barrier Reef World Heritage Area 1998 (Wachenfeld 1998), which notes that ‘reef fish numbers vary considerably from reef to reef and from year to year as a result of fluctuations in recruitment’.
  • There are regular ontogenetic shifts (life-stage related) and daily movement into and out of epibenthos. During the day, large numbers of coral reef fish are in the water column over benthic habitats (Lucas et al. 1997).

Conservation status

  • Queensland Nature Conservation (Wildlife) Regulation 1994: No marine fish species in the Great Barrier Reef is listed as threatened. However several are protected under Queensland fisheries legislation.
  • Queensland Fisheries Regulation 1995 lists species of fish that may be taken under each type of fishery (e.g. recreational, net, trawl, line) and specifies maximum and minimum sizes for some cod species. If the species is not listed, it cannot be taken. However, incidental take occurs, and in some fisheries, the amount taken exceeds that of the target species. These lists do not contain information about the conservation status of any species.
  • Environment Protection and Biodiversity Conservation Act 1999: No marine fish species in the Great Barrier Reef is listed as threatened.
  • Conservation Overview and Action Plan for Australian Threatened and Potentially Threatened Marine and Estuarine Fishes: 16 of the fish (non-sharks, rays, and syngnathids) occur in the Great Barrier Reef. A number of them are ‘lower risk’ (Table 6) and the majority are cod and groupers from the Family Serranidae.
  • IUCN: several bony fish species are listed by the IUCN Red Data Book (Table 3).

Human Related Threats

  • Boats, ships and other motorised machines
  • Coastal development
  • Declining water quality
  • Defence exercises
  • Fishing (overfishing), shark control programs and aquaculture
  • Hunting and collecting
  • Tourism and recreation

Actions

  • A Conservation Overview and Action Plan for Australian Threatened and Potentially Threatened Marine and Estuarine Fishes (Pogonoski et al. 2002) was compiled for  Environment Australia (now Department of the Environment and Heritage) by the Australian Museum and NSW Fisheries. The Species Conservation Program recommends to researchers that as few specimens as possible should be collected of species listed in the Conservation Overview.
  • The World Conservation Union has developed guidelines for applying the IUCN Red List Criteria to marine fishes.
  • The Queensland Government has introduced the Fisheries (Coral Reef Fin Fish Fishery) Management Plan 2003 to provide for the long-term sustainability of coral reef finfish stocks.
  • The Zoning Plan for the GBRMP prohibits the take of potato cod, barramundi cod and maori wrasse without prior permission from the GBRMPA. This mirrors regulations by the Queensland Department of Primary Industries and Fisheries. The Zoning Plan also bans the take without the written permission of the Authority of all Epinephelus spp. fish (ie: cod) greater than 100cm.
  • The GBRMPA also provides for the protection of threatened fish species through conditions on research permits, prohibiting the collection of some species via the Great Barrier Reef Marine Park Regulations 1983 and the protection of individual species at some high use locations (e.g. Cod Hole at Ribbon Reefs).
  • The location and protection of spawning grounds is now also being investigated.
  • The Species Conservation Program works with the Fisheries Issues Group of the GBRMPA to monitor and address concerns regarding fish conservation.

Marine Invertebrates

Knowledge

Conservation status

  • Marine invertebrates are not listed under Queensland’s Nature Conservation (Wildlife) Regulation 1994 and are not listed under the Commonwealth Environment Protection and Biodiversity Conservation Act 1999.
  • The Queensland Fisheries Act 1994 includes some marine invertebrates as “fish” for the purposes of the Act. The associated Fisheries Regulation 1995 lists species of fish that may be taken under each type of fishery (e.g. recreational, net, trawl, line). If the species is not listed, it cannot be taken (e.g. tritons, helmet shells). However, incidental take occurs, and in some fisheries, the amount taken exceeds that of the target species. These lists do not contain information about the conservation status of any species.
  • Brautigam (2001) notes that ‘although most marine organisms are invertebrates, only a few … have been assessed and included in the Red List (for example, the giant clams Tridacna spp.)’. The giant clams are also listed under the Convention on International Trade in Endangered Species of Wildlife Flora and Fauna (CITES).
  • A conservation overview of marine invertebrates in Australia was finalised in 2002 and published on the Australian Museum website. A summary of the main findings are:
  • Crustacea: for the majority of species, there is insufficient information to determine whether any species are threatened.
    • Taxa dependent on other groups of invertebrates or vertebrates:
      • Pyrgomatidae (dependent on hard tropical corals)
      • Archaeobalanidae (dependent on sponges, gorgonians)
      • Chelonibiidae, Coronulidae, Platylepadidae (epizoitic on turtles, whales, dolphins, dugongs)
  • · Molluscs:
    • Pearl oysters (Pinctada maxima, P.margaritifera) may be regarded as commercially threatened.
    • Overexploited: Tridacnidae, scallops
    • Potentially vulnerable through shell collecting: Cypraeidae (cowries), Volutidae (volutes), Conidae (Cones), Muricidae (muricids)
    • Taxa dependent on other groups of invertebrates:
      • Eulimidae (on enchinoderms),
      • Magilidae (on hard and soft corals),
      • Cerithiopsidae and Triphoridae (on sponges),
      • Mitridae (on sipunculans)
  • Sponges: Neptune’s Cup Sponge (Poerion neptuni also known as Cliona patera), was recently re-discovered off Cape York, after it was believed to have become extinct in the early 1900’s. The species is uncommon and very susceptible to benthic trawling. Status is considered threatened.
  • Other phyla: Insufficiently known to make an assessment

Human Related Threats

  • Coastal development
  • Declining water quality
  • Fishing, shark control programs and aquaculture
  • Hunting and collecting
  • Introduced species
  • Marine dredging and construction
  • Tourism and recreation

Actions

  • Provisions within the GBRMP Act and the Cairns Area, Whitsundays and Hinchinbrook Plans of Management prohibit people from damaging coral. ‘No Anchoring’ areas have been established at the following locations:
    • Whitsundays: Manta Ray Bay, Bait Reef, Blue Pearl Bay, Langford Island, Butterfly Bay, Maureen’s Cove, Luncheon Bay, Pinnacle Bay, Cateran Bay, Sunlover’s Bay, North Stonehaven Bay, South Stonehaven Bay and False Nara (Schedule 5, Whitsundays Plan of Management)
    • Hinchinbrook Area: Brook Islands
    • Cairns Area: Plan of Management Schedule 8 lists reef anchorages that are intended to encourage the use of places that are least likely to cause damage to coral.
  • Moorings have been installed in many Great Barrier Reef areas to also minimise anchor damage.
  • Best Environmental Practices for Anchoring have been prepared and publicised.
  • The conservation of marine invertebrates is being addressed through permit requirements.
  • Habitat conservation initiatives, such as the recently implemented Representative Areas Program, protects a representative network of a range of habitats under the revised reef-wide zoning system.
  • Marine pests are a threat to marine biodiversity and to marine industries such as fishing and aquaculture (Australian State of the Environment Committee 2001). There are a number of ways in which marine pests can be introduced into Australian waters including discharge of ship ballast water and fouling organisms on the ship hull and anchor chain. Since July 2001, mandatory ballast water management arrangements are in place for international vessels entering Australian waters. A baseline survey of the Port of Townsville and adjacent marine areas was carried out by James Cook University & CRC Reef scientists in November 2000. No target pest species have been identified to date. Further information can be obtained by emailing info@townsville-port.com.au.
  • The Department of the Environment and Heritage (formerly Environment Australia) is considering regulations for the access to biological resources in Commonwealth areas including access permits and benefit-sharing arrangements.
  • Since 1st January 2003, a global ban on the use of organotin compounds in ship anti-fouling systems has been in place through the International Convention on the Control of Harmful Anti-fouling Systems on Ships, 2001.
  • The Australian Institute of Marine Science is undertaking a seabed biodiversity assessment project to improve knowledge of marine biodiversity in northern Australia.
  • Additional information regarding marine invertebrates is available at the following websites:

Landscape format / medium shot / Bulbous solitary ascidian with orange rimmed siphons and purple-veined tunic on top of sponge and hydroid covered ascidians at Otter Reef

Ascidians      

  • The Australian Faunal Directory of the Australian Biological Resources Study (ABRS) has identified 736 species of ascidians that occur in Australia of which 536 have been described.               
  • Refer to The Outstanding Universal Value of the Great Barrier Reef World Heritage Area (Lucas et al. 1997). Summary follows from p.110:
    • At least 330 species of ascidians (also known as sea squirts) occur on the Great Barrier Reef, mostly over a vast range with the Great Barrier Reef acting as a bridge for gene flow from temperate to tropical areas. Gene flow probably occurs by a complex web of recruitment between the crowded populations occupying the profusion of habitats in the vast Indo-West Pacific coralline region.
    • From Barnes (1987): ascidians are encountered in all types of tropical marine habitats attached to rocks, shells, and pilings in shallow water, and on ship bottoms or sometimes fixed in mud and sand by filaments or a stalk. They exist as both solitary and colonial forms with body sizes ranging from 1mm-10cm in diameter.
    • They are non-selective filter feeders and strain large quantities of water for suitable food particles.
    • Ascidians are hermaphrodites (with a few exceptions), however cross-fertilisation is more typical than self-fertilisation.  Reproduction occurs either through budding (a small replica of the parent form that eventually frees itself from the parent) or through the release of sperm and egg into the water column (Barnes 1987, Kott 1982). The fertilised egg develops into a free-swimming tadpole larva with a notochord and neural tube, structures that show its linkage to the chordates. Within a short period of time (ranging from minutes to hours depending on the species) the tadpole larvae attach themselves to a substrate and metamorphose into miniature ascidians. The metamorphosed ascidian loses the notochord and the neural tube (Colin and Arneson1995).

Landscape format / close-up shot / undulating sheets of red and white Bryozoan, grouped in a head on reef platform.Bryozoans                                        

  • The Australian Faunal Directory of the Australian Biological Resources Study (ABRS) estimates that 2,500 species of  bryozoans occur in Australia of which 1,000 have been described.
  • Refer to The Outstanding Universal Value of the Great Barrier Reef World Heritage Area (Lucas et al. 1997). Summary follows from p.118:
    • Poorly known group, approximately 300-500 species occur on the Great Barrier Reef (8-12% of world fauna) forming natural ‘isolates’ that provide important structure and habitats for other species. It is likely that bryozoan fauna of reefal and shelf environments are distinct and that the Indo-West Pacific contains the highest diversity of bryozoans.
    • Cross-shelf variation is evident in the central Great Barrier Reef Marine Park (Birtles and Arnold 1988).
    • From Barnes (1987): bryozoans are sessile colonial animals composed of zooids. They are benthic, occurring in cryptic environments, in caves and under coral plates and generally found in reef and soft sediment shelf areas. Bryozoans are either encrusting, mobile epifauna, or anchored colonies attached to hard, stable substratum. They are inconspicuous, forming relatively small colonies ranging from millimetres to tens of centimetres in diameter.
    • Bryozoans are suspension feeders filtering the water column for small phytoplanktonic organisms.
    • Reproduction occurs either through the release of egg and sperm into the water column or fertilised eggs are brooded internally. A larval stage is usually present with settlement occurring on hard surfaces (rock, shells, coral and wood) with some species boring in calcareous substrates.

Crustaceans             

  • Landscape format / close-up shot / a group of colourful orange and white striped Hingebeak Shrimp, at mouth of caveThe Australian Faunal Directory of the Australian Biological Resources Study (ABRS) estimates that 9,871 species of crustaceans occur in Australia of which 7,111 have been described.
  • Refer to The Outstanding Universal Value of the Great Barrier Reef World Heritage Area (Lucas et al. 1997). Summary follows from p.126:
    • Poorly studied group with high diversity and low endemism. The extensive range of habitats occurring on the Great Barrier Reef is important for crustacean diversity. They live within all habitats in the Great Barrier Reef World Heritage Area (GBRWHA), from reefal environments to the inshore intertidal mangrove and seagrass habitats.
    • Endemism is low in reef fauna, but other habitats might have higher levels.
    • Highly diverse within most groups with a cosmopolitan Indo-West Pacific fauna.
    • GBRWHA species diversity reported as follows:
      • Barnacles: 100 species from more than 50 genera
      • Isopods: more than 150 species
      • Mysids: 50 species
      • Amphipods: more than 6000 known species from more than 1100 genera
      • Mantis shrimp, Krill and Crabs: 1030 species from 358 genera in 81 families; this represents about 50% of the Australian fauna
    • Anecdotal evidence suggests that inner-shelf reefs might have greater diversity than outer-shelf reefs.
    • Crustaceans are ecologically important as grazers, scavengers, predators and prey (Australian State of the Environment Committee, 2001).
    • From Barnes (1987): crustaceans have a great range of diets and possess a variety of feeding mechanisms including suspension feeding, predation or picking up food.
    • Reproduction occurs through copulation, and eggs are brooded for different lengths of time depending on the species. Crustaceans have free-swimming planktonic larvae that undergo several larval stages before developing into adult crustaceans.

Landscape format / close-up shot / a black-armed, yellow - pinnuled Featherstar, is attached by cirri to surface of hard coral covered with polyps feeding, at Gary's Lagoon, Bait Reef, 12m depth

Echinoderms            

  • The Australian Faunal Directory of the Australian Biological Resources Study (ABRS) estimates that 1,406 species of echinoderms occur in Australia of which 1,165 have been described.
  • Refer to The Outstanding Universal Value of the Great Barrier Reef World Heritage Area (Lucas et al. 1997). Summary follows from p.128:
    • 630 species including many rare taxa of echinoderms occur in the Great Barrier Reef with high phylogenetic diversity well expressed. The Great Barrier Reef is likely to have the greatest species diversity of echinoderms for any marine protected area in the world. The group contains distinct reefal and non-reefal suites of species with very strong zonation patterns that are associated with physical characteristics of the environment. They occupy all habitats and have an important role in structuring certain communities. For example, holothurians bioturbate sediments, resulting in destabilisation of sediment stratification, enhanced aeration and the release of organic material and nutrients from the interstitial water into the water column.
    • Echinoderms possess a range of feeding strategies:
      • Most feed by scraping algae, encrusting organisms and detritus from hard surfaces however some echinoderms, like urchins, are mobile, benthic grazers (Barnes 1987).
      • Crinoids are nocturnal plankton feeders, asteroids are carnivorous, opportunistic and scavengers and ophiuroids are filter-feeders (Gosliner et al. 1996).
      • Holothurians are restricted to hard substrate bottom sediments (Birtles and Arnold 1988) including clean sand (not mud based sand), coral reefs, silty sediments, seagrass and reef flats. They are found in waters 10 m to 40 m deep and their main food source is reported to be bacteria and detritus (Bakus 1973, Massin 1982, Poiner et al. 1998).
    • Echinoderms exhibit sexual reproduction (Smiley et al. 1991); larvae are plankton feeders that settle onto suitable substrate where they develop to young adults. Juvenile echinoderms are believed to be highly cryptic, with high numbers reported in seagrass habitats (Shelley 1981).

Landscape format / image of inshore coral reef -- unknown orginFringing reef corals and other reef elements                 

  • Refer to The Outstanding Universal Value of the Great Barrier Reef World Heritage Area (Lucas et al. 1997). Summary follows from p.137:
    • The majority of fringing reefs in the Great Barrier Reef World Heritage Area are found around continental islands with important sites located around complex island archipelagos, such as the Whitsunday Island group and the Palm Island group. A smaller number of fringing reefs border the mainland coast.
    • Fringing reefs exhibit high species diversity and contain some of the largest and oldest coral colonies in the Great Barrier Reef; genotype of some colonies may have been present on the reef for 1000s of years. Inshore coral communities in the southern Great Barrier Reef may offer new insights into coral reef formation and evolution.
    • Fringing reefs have a very high aesthetic value, in particular those areas that exhibit a high degree of heterogeneity, high coral diversity and high coral cover.
  • Refer to reefED for an overview about fringing reefs and other reef types.

Landscape format / close-up shot / tentacles are partially expanded from polyps on this pink Acropora coral, at North Point, Lizard Island, at depth of 5 metres.I/Neg.Hard Corals                          

  • For an overview on corals, visit reefED-GBR Explorer.
  • Refer to The Outstanding Universal Value of the Great Barrier Reef World Heritage Area (Lucas et al. 1997). Summary follows from p.152:
    • High diversity of habitats in the Great Barrier Reef World Heritage Area allows for the high diversity of hard corals encountered in the area; 359 hard coral species have been recorded, however endemism of the group is low.
    • Long-lived massive corals can provide historical information of environmental conditions.
    • Hard corals play an important role in the ecology of tropical seas by building highly productive and massive reefs (Colin and Arneson 1995).
    • From Barnes (1987): most hard corals feed at night, however many species also feed during the day using their tentacles to capture anything from zooplankton to small fish. The tentacles are also used during competitive encounters with other corals. Corals lacking tentacles are suspension feeders capturing prey in mucous strands.Reef-dwelling (hermatypic) corals contain symbiotic zooxanthellae algae that transfer a large portion of their fixed carbon (produced during photosynthesis) to the coral for use in growth. The coral in turn, probably supplies the zooxanthellae with nitrogen obtained from particles captured by the coral.
    • Hard corals exhibit both asexual and sexual reproduction with several variations depending on the species. They can be hermaphrodites or have separate sexes, with fertilisation being either internal (sperm is released into the water column where it locates a female with eggs) or external (both eggs and sperm are released into the water column). A planulae larva is produced and is capable of long distance dispersal before it settles to the bottom, where it starts to create a calcium carbonate skeleton (Colin and Arneson 1995). This skeleton later serves as protection and support for the coral.

Landscape format / close-up shot / a Cone shell with striking brown and white markings on shell and siphons, moves across Favia hard coralMolluscs                   

  • The Australian Faunal Directory of the Australian Biological Resources Study (ABRS) estimates that 12,472 species of molluscs occur in Australia of which 9,512 have been described.
  • Refer to The Outstanding Universal Value of the Great Barrier Reef World Heritage Area (Lucas et al. 1997). Summary follows from p.165:
    • 5000-8000 species of molluscs occur in the Great Barrier Reef representing a significant proportion of the world molluscan diversity. There are four main components of molluscan fauna with the most speciose being the shallow reefal fauna with very low endemism.
    • Endemism is highest in components shared with southern Qld and NSW; the volute family has the highest degree of endemism.
    • Some bivalves play an important role in bioerosion of coral substrates.
    • Poorly known groups, especially smaller taxa, exist in coastal waters with largest terrigenous inputs and attenuate with increasing latitude.
    • Most gastropods have a single shell and occupy most niches in the marine environment.
    • They exhibit a wide array of feeding strategies (deposit feeding, herbivorous, carnivorous, parasitism); bivalves are predominantly filter feeders and have two shells, many are infaunal burrowers or attach themselves to substrate; cephalopods are efficient swimmers, predators (carnivores) and some have a full shell (nautilus) while others have no shell (octopus).
    • From Barnes (1987): Modes of reproduction vary among classes; some are hermaphrodites whereas others release sperm in the water current with fertilisation occurring in the sea or in the mantle cavity of the females. A free-swimming larva is typical of some molluscs (e.g. bivalves).

Landscape format / extreme close-up shot / extended polyps on yellow-ochre coloured Flower soft coral

Octocorals                

  • Refer to The Outstanding Universal Value of the Great Barrier Reef World Heritage Area (Lucas et al. 1997). Summary follows from p.174:
    • Poorly investigated group, 80 genera likely to occur on the Great Barrier Reef of 270 worldwide. The group consists of sea pens, soft corals and gorgonians and they occur in all habitats; in the Great Barrier Reef World Heritage Area they are known to occupy both reefal and inter-reefal habitats. Soft corals are a major component of sessile benthic fauna and contribute significantly to the aesthetic value of the reefal environment.
    • From Colin and Arneson (1995): Octocorals possess eight tentacles and calcareous spicules (often used for identification) that aid the support and maintenance of shape in large colonies.
    • They are opportunistic competitors of space on the reef and rapidly cover available substrate. They are filter feeders of plankton and inhabit areas where currents flow. Several species contain symbiotic zooxanthellae that augment nutrient intake.
  • Octocorals exhibit both asexual and sexual reproduction strategies including broadcast spawning, internal fertilisation, and brooding (P. Alderslade personal communication as cited by Conservation overview of marine invertebrates 2002).
  • ReefED provides an overview on soft corals and gorgonians.

Landscape format / medium close-up shot / Elongate white flatworm with central white and orange, purple-margined strip, and outer purple margin, on GBR reef wallPlatyhelminths                     

  • The Australian Faunal Directory of the Australian Biological Resources Study (ABRS) estimates that 10,806 species of platyhelminths occur in Australia of which 1,506 have been described.
  • Refer to The Outstanding Universal Value of the Great Barrier Reef World Heritage Area (Lucas et al. 1997). Summary follows from p.135:
    • Thousands of species of platyhelminths occur in the Great Barrier Reef with low endemism, high diversity in free-living macro and meiofaunal forms and very high diversity in parasitic forms. There are likely to be distinct reefal and inter-reefal faunas across the shelf.
    • Polyclad turbellarians with vivid colours and patterns contribute to the Reef’s aesthetic value and cosmopolitan composition with Indo-West Pacific environments.
    • Four groups of flatworms: macrofaunal (large free-living), meiofaunal (small free-living), interstitial (less than 1 mm) and symbiotic (Cannon 1993).
    • From Barnes (1987): Platyhelminths can be predators, scavengers, herbivores, commensals or parasites and they feed on a wide range of prey.
    • Most platyhelminths are hermaphrodites, with the exception of a few specialised parasitic species. Reproduction occurs through copulation and internal fertilisation. Development of eggs is either direct or can in some species develop indirectly into planktotrophic larvae.

Landscape format / close-up shot / pale pink feathery brachial crown, of a FeatherwormPolychaete worms               

  • The Australian Faunal Directory of the Australian Biological Resources Study (ABRS) estimates that 3,239 species of polychaetes occur in Australia of which 1,139 have been described.
  • Refer to The Outstanding Universal Value of the Great Barrier Reef World Heritage Area (Lucas et al. 1997). Summary follows from p.178:
    • Tropical fauna is poorly known. Polychaetes are dominant macrofauna in reefal sediments and coral substrates with 80 species recorded in the Great Barrier Reef, however >500 species may occur. Diversity is a product of latitudinal extent, habitat diversity and good condition of the Great Barrier Reef.
    • Polychaete worms play important roles in the ecosystem, for example, they are important in the food chain both as a predator and prey; they dominate macrofauna both in terms of numbers of individuals and number of species. They bioturbate sediments and are one of the first colonisers of dead coral colonies, facilitating settlement of other invertebrates.
    • Polychaetes probably exhibit latitudinal and cross shelf variations; some with restricted distributions.
    • Polychaetes occur in all habitats from mangroves, seagrass beds, inter-reefal sediments and within reef structure as borers, nestlers and encrusters; some are pelagic. Species composition is determined by sediment characteristics, water movement and stability of sediments.
    • Feeding strategies include: deposit feeders, herbivores, filter feeders, suspension feeders and omnivores. Polychaetes are either opportunistic, selective or non-selective, feeding on bacteria, algae, detritus, other invertebrates and carrion (Barnes 1987, Lucas et al. 1997).
    • Polychaetes have a range of reproductive strategies, including brooders and broadcast spawners, exhibiting sexual and asexual reproduction. Life cycles last from a few weeks to several years.

Landscape format / close-up shot / cream coloured Tube Sponge with elongate tubes, attached to coral wall at Hardy ReefSponges                   

  • The Australian Faunal Directory of the Australian Biological Resources Study (ABRS) estimates that 3,500 species of sponges occur in Australia of which 1,416 have been described.
  • Refer to The Outstanding Universal Value of the Great Barrier Reef World Heritage Area (Lucas et al. 1997). Summary follows from p.191:
    • 1500 species of sponges occur in the Great Barrier Reef (c. 30% of Australian sponge fauna), endemism is likely to be low, but lacks study. Relicts of reef-building sponges from Ordovician Period have been recorded and cross shelf trends in sponge abundance and diversity are exhibited.
    • Sponges play a significant role in ecosystem processes; some sponges live off the products produced by symbiotic cyanobacteria while other sponges live off the detritus and waste products that filter down in the water column. They are an important food source for the threatened hawksbill turtle and also function as a host to multitudes of other organisms including crustaceans, molluscs, worms, echinodems and microorganisms (Australian State of the Environment Committee 2001).
    • Species richness decreases with increasing distance from the shore (Wilkinson and Cheshire 1989).
    • From Barnes (1987): Sponges are sessile, occurring on benthic substrate wherever rocks, shells, submerged timbers or coral provide a suitable substratum, even on soft sand or mud bottoms. Availability of space, inclination of the substrate and current velocity influence the growth of sponges. A variety of growth forms exists from burrowing to encrusting to those that attach to a relatively small area and grow upright with branches or into large urn shapes. Sponges inhabit shallow coastal waters to depths of 200 and 1000m.
    • Sponges are sedentary filter feeders; water enters the sponge through inhalent canals and is filtered for food particles and oxygen (Colin and Arneson 1995).
    • Exhibit both sexual and asexual reproduction, with many sponges being hermaphrodites producing both eggs and sperm. A free-swimming larva develops from the fertilised egg. Asexual reproduction can occur through budding or fragmentation from the adult sponge.

Landscape format / close-up shot / wavy swirls of Funnel weed, in shallow waters at Low Isles

Marine Plants                 

Knowledge

  • Refer to The Outstanding Universal Value of the Great Barrier Reef World Heritage Area (Lucas et al. 1997) as follows for summaries relating to Great Barrier Reef:
    • Algae(p.108) and Halimeda banks(p.149): 400-500 species of macroalgae (20 species of Halimeda), high diversity and low endemism, highly variable showing latitudinal, cross-shelf and within-reef variation in composition and abundance, important in cementing reef structures, contributors to sediments, primary producers and as a food. Red algae are the most diverse group, and are more abundant and diverse inshore, as are the brown algae. Green and red algae dominate offshore areas. The Great Barrier Reef has the most extensive, actively accumulating Halimeda beds in the world.
    • Mangroves(p.155): 37 species (54% of world flora), comparable and complementary diversity to other areas of high diversity, important contributor to ecological processes.
    • Seagrasses(p.183):15 species and others undescribed, at least two appear to be endemic, several species are at latitudinal limits, extensive deep water meadows, important in ecological processes and as fish and prawn nurseries; typically found in localities sheltered from prevailing south-easterly trade winds; found in intertidal and subtidal locations, from 2.2m above to 60m below mean sea level. Important food resource for many animals, especially fishes, and threatened dugong and green turtle; diversity decreases with increasing latitude (Leis and Rennis 1983).
  • Refer also to pages 35-36 of State of the Great Barrier Reef World Heritage Area 1998 (Wachenfeld 1998), which notes that ‘despite concerns that algae may be taking over some inshore reefs, there is no strong evidence as to whether macroalgal cover is generally increasing on these reefs’ p.36.

Conservation status

Human Related Threats

  • Boats, ships and other motorised machines
  • Coastal development
  • Declining water quality
  • Defence exercises
  • Fishing
  • Marine dredging and construction
  • Tourism and recreation

Actions

  • Dugong Protection Areas were established for conservation of dugongs and the protection of seagrass habitats.
  • Fish Habitat Areas established under the Queensland Fisheries Act 1994 provide a high level of protection for marine plants and associated habitats.
  • The GBRMPA and the CRC Reef have funded baseline seagrass surveys in many areas of the Great Barrier Reef.
  • A recent Fisheries Research and Development Corporation review of seagrass in Australia (Butler and Jernakoff 1999) resulted in the formulation of a seagrass research and development (R&D) plan. One important aspect of the R&D plan was to form an inter-agency network ‘to facilitate co-operation between the agencies in the funding and coordination of research, the effective use of research outcomes and the improvement of management’. This network would then facilitate research projects identified in the review.
  • The Queensland Department of Primary Industries and Fisheries manages seagrass, mangroves and other marine plants. The Queensland Department of Primary Industries and Fisheries requires permits be obtained before the removal of marine plants.
  • The conservation of marine plants in the GBRWHA will be achieved mainly through habitat conservation initiatives, such as the Representative Areas Program, which will ensure comprehensive, adequate and representative protection of examples of the entire range of habitats including associated marine plants.

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