This article has been reviewed according to Science X's editorial process and policies. Editors have highlighted the following attributes while ensuring the content's credibility: Spiny lobster larvae spend six to nine months drifting in the open ocean, feeding within the plankton community, before eventually settling into shallow-water habitats such as mangroves, seagrass beds or coral reefs. This means the number of young lobsters reaching Bermuda is strongly influenced by ocean conditions across the wider North Atlantic and Caribbean region.
By combining catch-per-unit-effort records from Bermuda's commercial lobster fishery, contributed by the Department of Environment and Natural Resources (DENR), with long-term observations from the Bermuda Atlantic Time-series Study (BATS) at ASU BIOS and satellite measurements of photosynthesis in the ocean, researchers have developed a new index. It tracks changes in the ocean and the plankton food chain and links them to the supply of larvae needed to replenish Bermuda's spiny lobster population. The findings are published in the journal Communications Earth & Environment.
The authors found that the regional ocean has been warming while primary production, measured via satellite images, has declined. In parallel, changes in the zooplankton community suggest that the transfer of energy up the food chain is becoming less efficient. Together, these changes may mean less nutrition is available to lobster larvae during their months drifting in the open ocean, as well as to juvenile lobsters and other animals higher in the food web after settlement.
The researchers combined these factors into a new "trophodynamic index." The index explained changes in lobster catch rates better than temperature, primary production alone, previous catch levels or long-term average conditions. Forecasts based on the index also outperformed these alternative approaches. Lead author Leocadio Blanco-Bercial, an associate professor in the Arizona State University School of Ocean Futures, said one of the most exciting aspects of the research is the ability to bring together datasets that individually provide only part of the picture.
"Combining data from Bermuda's fishermen and fisheries with long-term observations from BATS and satellite imagery allows us to address a question that could not be answered by any of these datasets alone," Blanco-Bercial said. The study demonstrates how collaboration between government, scientists and Bermuda's fishing community can draw on decades of scientific, environmental and fisheries data to create a practical tool for resource managers. "Sustainable fisheries management depends on understanding not only what is happening within the fishery, but also the environmental conditions that affect our fishery species," said Tammy Warren, senior marine resources officer at DENR.
"As our ocean changes, integrating different types of evidence will become increasingly important to making informed management decisions." "Most fishery monitoring is based on looking at changes in the catch after those changes have happened," said Joanna Pitt of DENR. "The major benefit of this index is that it can give us some advance warning of changes that are affecting the early life stages of the spiny lobster, so that we can be prepared to adjust our management approaches." Fernando Taboada of the Spanish Institute of Oceanography of the Spanish Research Council (IEO-CSIC), who also collaborated in the study, stressed that the research brings a fresh perspective to the management of invertebrate fisheries: "It is clearly important to take into account the planktonic larval phase." The complex life cycle of the spiny lobster presents a variety of management challenges. The new index is therefore not intended to replace existing fishery monitoring or management tools, but it can complement current approaches, improve forecasts and support more ecosystem-based fisheries management.
Extract — continue reading at the source.
