Can We Manage Marine Mammal Bycatch Effectively in Low-Data Environments?

Potential Biological Removal (PBR) is a common way to identify the maximum amount of human-caused marine mammal mortality (i.e. bycatch mortality) that can occur for a species to recover to or maintain its optimum sustainable population size. This method, however, requires unbiased estimates of absolute abundance for the marine mammal population being managed. This is not feasible when limited resources or capacity hinder the amount and type of data collected.

In a new study, researchers explored three alternative methods that may help in low data conditions when only data on trends in abundance were available: The Depletion-corrected Average Catch (DCAC) method, The Slope method, and The Replacement Yield (RY) method. These methods can be used to determine levels of bycatch mortality consistent with the objectives of PBR. The Slope and RY methods performed best in data-limited scenarios while the DCAC was not advocated for use under any scenario.

Read the full paper.

Reference

Punt, A.E., Siple, M., Francis, T.B., Hammond, P.S., Heinemann, D., Long, K.J., Moore, J.E., Sepúlveda, M., Reeves, R.R., Sigurðsson, G.M., Vikingsson, G., Wade, P.R., Williams, R., Zerbini, A.N. (2021). Can we manage marine mammal bycatch effectively in low-data environments? Journal of Applied Ecology. https://doi.org/10.1111/1365-2664.13816