Marine – Field Talk

Spearfishing to depletion in Chile

liza — Fri, 01 Oct 2010 20:19:43 +0000

Spearfishers in Chile

In theory, the evolution of scuba gear and wetsuits in spearfishing allow divers to produce a more abundant catch. However, Natalio Godoy from the Pontificia Universidad Católica de Chile and colleagues found that the spearfishers’ catches are becoming less diverse and abundant in the temperate reefs in northern and central Chile. The result, as they suggest in a recent study published in Ecological Applications, is likely due in part to the spearfishing activities themselves.

Godoy and colleagues used several methods to obtain information on the state of reef fish communities in Chile since records of spearfishing activities, and landing records specific to certain regions, are not required by the government. Therefore, the researchers examined data from nation-wide official landing records, the catch from the top 20 divers in the 1971 and 2004 world spearfishing championships and the perceptions of local spearfishers.

They found that the average mass of reef fish captured decreased, the percentage of discarded fish decreased and the total number of species caught decreased drastically in the 30 year span between championships. The interviews, on the other hand, contributed an even greater understanding of the status of the fisheries: Divers reported that they were catching, and local markets were accepting, species of fish that were not consumed just 10-15 years ago.

Stepping stones of diversity: the Santa Barbara landscape and giant kelp genetics

liza — Mon, 01 Mar 2010 22:06:00 +0000

What is it about the rocky habitat in California that makes giant kelp so prevalent? And how do they spread from one section of the Santa Barbara Channel to another? According to Filipe Alberto, a marine population geneticist at the Centre for Marine Sciences in Portugal, giant kelp spread from one area to another in a stepping stone fashion, changing their genetic make-up as they go along. In his study, published in the January issue of Ecology, Filipe and colleagues analyzed the effects of isolation on genetic diversity between kelp forests. Diving with researchers from the University of California, Santa Barbara, Filipe collected all the samples he needed to study their genetic diversity—and he did it in just two weeks at the coastal Long Term Ecological Research (LTER) site in Conception, California. The samples, which were then shipped back to Portugal, showed that habitat continuity plays an important role in genetic connectivity.

Seasonality and climate change

liza — Tue, 31 Mar 2009 21:29:22 +0000

Rising temperatures as a result of climate change promise to alter the behaviors of temperature-sensitive organisms. But climate change is also affecting the timing of seasons, which can throw off the alarm clock for critical behaviors, such as breeding. In this edition of Field Talk, we speak with Shaye Wolf, a biologist at the Center for Biological Diversity in San Francisco. Her research, published in the March issue of Ecology, tracks the reproductive behaviors of a small seabird, Cassin’s Auklet, on islands from Alaska to Mexico. She explains that climate change affects different populations in different ways, but could have dire consequences for those that rely heavily on consistent seasonality.

To fly or not to fly? Diving birds shun air travel

liza — Tue, 18 Nov 2008 17:22:28 +0000

The ability to fly is one of the most significant adaptations in animal history. Some birds, however, have opted out of flying – evolutionarily speaking. In this installment of Field Talk, we catch up with Dr. Rory Wilson, a professor of aquatic biology at the University of Swansea. His paper in the November issue of Ecological Monographs examines the Galápagos cormorant, an aquatic bird that hunts seafloor prey off the coasts of the islands where it makes its home. Wilson and his colleagues find that the peculiar conditions on and around the islands has led to the loss of flight in these cormorants, a trade-off that gives these birds better diving ability.

Dead Zones as Safe Havens

liza — Fri, 10 Oct 2008 14:39:18 +0000

Andrew Altieri, a postdoctoral fellow at Brown University, joins us in this month’s episode of Field Talk to discuss his work examining hypoxic marine systems, known as dead zones. Altieri studies a community of clams and mussels – collectively known as bivalves – in Narragansett Bay, off the coast of Providence, Rhode Island. His paper in the October issue of Ecology shows that one species of bivalve, the quahog, can benefit from reduced oxygen content in the water. The resulting boom in quahog populations has important implications for ecosystem services.

Arctic Marine Mammals

liza — Wed, 23 Apr 2008 18:02:36 +0000

Timothy Ragen, Executive Director of the Marine Mammal Commission, talks about a special issue of Ecological Applications which focuses on arctic marine mammals and climate change. The Commission supported publication of the Supplement issue, which features a cross-section of experts offering their insights to the future of arctic marine mammals. Ragen talks about which species may be most vulnerable to climate change.