Fish and Fisheries

Sydney Harbour is host to around 580 species of fish, making it amongst the most bio-diverse estuaries for fish in the world.

This diversity underpins the important social and economic value of the Harbour, supporting activities such as snorkelling, SCUBA diving and recreational fishing. The Harbour is also a nursery for juvenile fish of many species which are the basis of important commercial fisheries outside the Harbour.

This rich fish diversity is likely linked to the variety of habitats available throughout the Harbour but the details of these relationships are not well understood. As key habitats such as seagrass, mangrove and natural intertidal areas are rapidly being lost throughout the Harbour, it becomes increasingly critical to understand the nature of these links to biodiversity.

This theme will focus on better understanding the dynamics of fish populations within the harbor, their key drivers and their impact on the socio-economic benefit of key user groups.

Collaborators

Sydney Harbour Research Program scientists (Assoc. Prof. Will Figueria (USYD), Prof. David Booth (UTS), Prof. Iain Suthers, (UNSW) and A/Prof Melanie Bishop (UMQ) are working alongside government agencies NSW Department of Primary Industries and independent funding bodies Recreational Fishing Trust to address this gap in knowledge.

Projects

Green engineering seawalls – Impacts on fish assemblages

This project is working in collaboration with A/Prof Melanie Bishop at Macquarie University to look at the impacts of the green enginerring of seawalls on populations of both cryptic fishes associated directly with seawalls, as well as less tightly associated fishes that utilise seawall areas. The project will specifically evaluate the role of the remediated habitats as sources of additional structural complexity, food and modifiers of community (predator/prey) landscapes.

Evaluating impacts of soft sediment restoration on associated fish assemblages

This project builds from several soft-sediment rehabilitation projects occurring within the Harbour (described within the Habitat Restoration theme). The additional structure and food resources provided by restored soft sediment habitats are likely to boost the use of these areas by resident fishes.  This project seeks to quantify patterns of use and to evaluate the longer-term benefits these habitats may have on local fish communities.