“Every single spot of the ocean along the West Coast is affected by 10 to 15 different human activities annually”, says Ben Halpern, a marine ecologist at the National Center for Ecological Analysis and Synthesis (NCEAS) at the University of California at Santa Barbara.

In a two-year long study, Halpern and his colleagues have documented the way humans are affecting the ocean off the West Coast of the United States. The research team has overlaid data on the location and intensity of 25 human derived sources of ecological stress, including commercial and recreational fishing, land-based sources of pollution, and climate change. The information has been used to construct a composite map of the status of West Coast marine ecosystems.

“We found two remarkable and unexpected results in this research,” says Halpern. “Ocean management needs to move beyond single-sector management and towards comprehensive

ecosystem-based management if it is to be effective at protecting and sustaining ocean health. Also, the global** results for this region were highly correlated with the regional results, suggesting that the global results can provide valuable guidance for regional efforts around the world.”

The study results show that hotspots of cumulative impact are located in coastal areas close to urban centres and heavily polluted watersheds.

“This important analysis of the geography and magnitude of land-based stressors should help focus attention on the hot-spots where coordinated management of land and ocean activities is needed,” said Phillip Taylor, section head in NSF’s* Division of Ocean Sciences.

You can find more information in the article from the research team published in the journal Conservation Letters on May 11. The project was conducted at NCEAS, which is primarily funded by NSF’s Division of Environmental Biology.

* National Science Foundation (NSF)

** The lead scientists on the U.S. study have already carried out a similar analysis on a global scale; the results were published last year in Science.

U.S. and Canadian scientists have documented the first known migration of blue whales from the coast of California to areas off British Columbia and the Gulf of Alaska since the 1965 ban of commercial whaling.

Researchers identified 15 separate cases where Blue Whales were spotted in the waters off British Columbia and the Gulf of Alaska. Four of the observed animals were identified as Blue Whales previously seen swimming in Californian waters, which suggests that Blue Whales are re-establishing their old migration pattern.

The identifications were made by comparing pictures of Blue Whales photographed in the northern parts of the Pacific Ocean since 1997 with photographs of Blue Whales taken off the southern U.S. West Coast. The identity of individual Blue Whales was determined based on dorsal fin shape and pigmentation patterns in skin colour.

The Blue Whale was almost hunted to extinction during the 20^th century and even though commercial whaling has been prohibited (albeit not strictly enforced) since 1965 the populations are having a hard time recovering. Blue Whales are still listed as endangered on the IUCN Red List of Threatened Species and no more than roughly 5,000 to 12,000 Blue Whales are believed to remain in our oceans, with 2,000 of them living of the U.S. West Coast.

The migration research was conducted by scientists from Cascadia Research Collective in Washington State, NOAA’s* Southwest Fisheries Science Center in California, and Canada’s Department of Fisheries and Oceans. You can read the full article in the most recent issue of the journal Marine Mammal Science.

* The United States National Oceanic and Atmospheric Administration (NOAA)