SEAS- Scavengers of Eastern Australian Seas

Points covered:

• What does the SEAS project study?
• Why is the SEAS project significant?
• What has the SEAS project done so far?

Words to know:

• GUILD - a group of species with similar resource requirements and foraging strategies.
• SCAVENGERS - animals that feed on carcasses or organic refuse.
• TAXONOMY - the naming and classifying of plants and animals.
• DEMERSAL - living on, or near the bottom of the sea.

The SEAS project studies guilds of marine scavengers along the entire east coast of Australia. It started in 1993 and is conducted by scientists from the Australian Museum. The SEAS project aims to:

• investigate current concepts of the ecology, taxonomy and evolution of scavenging crustaceans;
• establish a basis for further study of these crustaceans; and
• deal with the trap fishery problems in eastern Australian waters.

The SEAS project is significant because marine demersal scavengers are vitally important as they decompose dead organisms, recycle nutrients through marine ecosystems and are major pests in trap fisheries.

In most marine environments scavengers are both diverse and abundant. They range from large sharks to minute ostracods. But in the demersal marine environment the invertebrate scavenging guild is dominated by crustaceans.

Crustacean scavengers are the subject of many ecological and physiological studies. However, most research into crustacean scavengers has focused on a limited number of species or just one component of the scavenging guild. There are few studies that consider the entire guild as the SEAS project does.

Australia is a good place to study demersal crustacean scavengers because it has a continuous coastline from tropical to cold temperate environments where crustacean scavengers are diverse, abundant and widespread. It also has a large trap fishing industry in which scavenging crustaceans are a widespread pest.

In 1993, the SEAS project began a three year ecological study of the scavenging guilds of the eastern Australian continental shelf and slope. Replicate samples were taken at six locations off the coast eastern Australia - Cairns, Gladstone, Mooloolaba, Coffs Harbour, Wollongong and Hobart. At each location three replicate samples were taken at six depths, ranging from 50 metres to 1000 metres. Sea floor temperatures and sediment samples were also taken at each depth. The largest animals caught were conger eels, up to two metres in length and the smallest were cypridinid ostracods, about two millimetres in length.

All sampling has been completed and the majority of samples to be used in the final analyses sorted. Over 200 species have been identified and about 800,000 individuals counted and weighed.

Jim Lowry
Marine Invertebrates