Population structure of humpback whales in the southeastern Caribbean: an update
Peter Corkeron, Richard M Pace III and Sofie M Van Parijs
The current status of the populations of humpback whales breeding in Caribbean waters remains unresolved. Complicating the status assessment, is there are two competing hypotheses to explain the stock structure of humpback whales in Caribbean waters; 1 versus 2 stocks. The two-stock hypothesis is that there is a larger, more northern stock occurs in Caribbean waters in December to early March, and a second, smaller population occurs in the more southeastern part of the Caribbean from mid-March to late May. If any of the humpback whales hunted in the St Vincent and the Grenadines Aboriginal Subsistence fishery are taken from late March to June, then they may be from a stock for which there is no estimate of abundance. The Caribbean Humpback Acoustic Monitoring Project (CHAMP) was a multi-institutional cross-Caribbean survey that used passive acoustic recorders, in December 2016 to June 2017, to investigate the relationship between the southeastern and northern Caribbean animals. The timing of recorded songs supports the two-population hypothesis. However, a definitive answer will require a more substantial biopsy/photographic sampling program in the southeastern Caribbean at the appropriate time (late March â€“ June), coupled with sampling in the waters off Iceland, Norway, and elsewhere off northern Europe, and matching across sampling programs to develop a mark-recapture abundance estimate of animals from the waters of the southeastern Caribbean. Also a further analysis of the characteristics of the songs recorded by CHAMP might shed more light on the feeding grounds used by animals in the southeastern breeding grounds.