Image: Location and numbers of reef life survey sites worldwide.
Reef Life Survey (RLS) conducts long-term monitoring of coastal habitats which are carried out by volunteer recreational divers trained to a scientific level of data collection.
It also links marine scientists, managers and recreational divers, raises public awareness about the health of the inshore environment, and improves community participation in coastal monitoring.
Reef Life Survey provides Australia’s most comprehensive, quantitative coastal marine biodiversity baseline data. These support the identification of indicators for change. Standardised surveys now cover more than 3000 species and 1500 sites in Australia and more than 2400 sites worldwide, providing the foundation for a global analysis of how marine protected areas affect the recovery of species. This project analysed the global RLS dataset to identify management features typical of effective marine protected areas (MPAs).
Video: Edgar & Stuart-Smith, finalist, 2014 Eureka Prize for Environmental Research
Approach
Many factors influence the rate and magnitude of the recovery of species populations following the declaration of MPAs. They include: MPA size, age, local regulations, fishing pressure, level of compliance, and water temperature. Statistical analysis of data from tens to hundreds of MPAs was required to determine how these factors interact. This project involved analysis of five years of Reef Life Survey data obtained in 87 MPAs and 40 countries: the largest worldwide investigation with standardised quantitative data. Divers used a consistent methodology to survey numbers and sizes of all fishes sighted underwater along 50 m by 5 m transect blocks. Total fish biomass increase in MPAs was used as a proxy for conservation effectiveness.
Key findings
The global analysis found that while some MPAs were extremely effective, more emphasis was needed on MPA design, long-term regulation of fishing practices, and compliance to ensure MPAs achieved their full conservation value. While more than half of the MPAs studied could not be distinguished ecologically from fished areas, fish biomass had been reduced by more than two-thirds on fished reefs worldwide compared with effective MPAs.
Conservation benefits increased exponentially with the accumulation of five key features: regulations that prohibit all fishing, effective enforcement, greater age (>10 years), large size (>100 km2), and geographic isolation due to deep water or sand. The influence of these five features differed among discrete elements of the reef fish community. MPAs with all five key features had twice as many large (>25 cm) fish species per transect, nine times more large-fish biomass, and 39 times more sharks than fished areas.
Additional findings
A Reef Life Survey expedition in the Coral Sea Commonwealth Marine Reserve for the Marine Biodiversity Hub found Coral Sea reef animals to be distinctly different from those of the Great Barrier Reef (GBR). This was due to the predominance of species associated with offshore islands, and the presence of fewer fishes and invertebrates typical of the GBR. Overall, Coral Sea reef communities were more closely related to Polynesian reefs than to mainland Queensland reefs, despite vast differences in proximity (see story Surveys of Commonwealth marine reserves: Coral Sea).
IMAGE: A Whitetip Reef Shark (Triaenodon obesus) at West Islet in the Coral Sea CMR. Marine protected areas with the five key features identified in this project have 39 times more sharks than fished areas. Image: Reef Life Survey.
New knowledge and opportunities
Globally, more than 4500 species of fishes, mammals, sea snakes, turtles, and invertebrates have been assessed, each at about 100 sites on average. More than 2400 sites and 14,000 transect blocks have been surveyed, and the network of trained RLS divers has been broadened.
Reef Life Survey has demonstrated its value in establishing baselines and providing data for evaluating and comparing the status of MPAs: both between MPAs, and with the adjacent environment. It has further potential as an ongoing monitoring tool. Comparative data from the University of Tasmania (IMAS) long-term MPA monitoring program show that fish, invertebrate and macroalgal populations continue to change in MPAs relative to baseline conditions and nearby fished areas for up to 20 years due to interactions within the food web.
Reef Life Survey provides a scientifically rigorous yet cost-effective approach for consistent, long-term Australia-wide monitoring of shallow reef condition that would contribute to State of the Environment reporting.
Outputs and outcomes
This project has delivered improved tools for mapping the distribution of marine biodiversity. Reef Life Survey data have facilitated an improved understanding of the management conditions necessary for MPAs to effectively achieve conservation goals, of threats to marine ecosystems, and of threatened marine species. Public engagement in marine conservation has also been boosted through Reef Life Survey.
contact
Graham Edgar
g.edgar@utas.edu.au
0427 811 699