Saving endangered whales at no cost

Author Posting. © Elsevier B.V., 2007. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Current Biology 17 (2007): R10-R11, doi:10.1016/j.cub.2006.11.045.The North Atlantic right whale is one of the most critically endangered marine species. Drastic overexploitation has driven this large, slow-swimming baleen whale to virtual extinction in Europe, while a small remnant population of ~350 individuals remains on the U.S. and Canadian east coast. Although this species has been protected for 70 years, recovery has been slight and extinction is still looming because of accidental mortality from shipstrikes and fishing gear (Figure 1A,B). Seventy five percent of appropriately photographed whales show evidence of entanglement, predominantly with lobster fishing gear, and this percentage has increased from 52% in the 1980s. At the same time, the U.S. lobster fishery is severely overexploited (the inshore fishing mortalities in the two main U.S. regions are 0.69 and 0.84, while 0.2 achieves maximum yield per recruit). We argue here that this endangered whale species can be protected from entanglement mortality, and the fishery can benefit simultaneously, by a large reduction of lobster traps used; a classic win–win situation.This work was supported by the Lenfest Foundation and NSERC

Mixed evidence for reduced local adaptation in wild salmon resulting from interbreeding with escaped farmed salmon: complexities in hybrid fitness

Interbreeding between artificially-selected and wild organisms can have negative fitness consequences for the latter. In the Northwest Atlantic, farmed Atlantic salmon recurrently escape into the wild and enter rivers where small, declining populations of wild salmon breed. Most farmed salmon in the region derive from an ancestral source population that occupies a nonacidified river (pH 6.0–6.5). Yet many wild populations with which escaped farmed salmon might interbreed inhabit acidified rivers (pH 4.6–5.2). Using common garden experimentation, and examining two early-life history stages across two generations of interbreeding, we showed that wild salmon populations inhabiting acidified rivers had higher survival at acidified pH than farmed salmon or F1 farmed-wild hybrids. In contrast, however, there was limited evidence for reduced performance in backcrosses, and F2 farmed-wild hybrids performed better or equally well to wild salmon. Wild salmon also survived or grew better at nonacidified than acidified pH, and wild and farmed salmon survived equally well at nonacidified pH. Thus, for acid tolerance and the stages examined, we found some evidence both for and against the theory that repeated farmed-wild interbreeding may reduce adaptive genetic variation in the wild and thereby negatively affect the persistence of depleted wild populations

Eutrophication and recovery of the Great Lakes

Meeting: World Commission on Environment and Development, Public Hearing, 26-27 May 1986, Ottawa, ON, CARelated to DAP 87-4249 under which IDRC supported the WCED to acquire and duplicate original papers, submissions, tapes and transcripts, became the depository of all original archival materials and received the right to microfiche the collection for broader disseminatio