Environment & Energy

hatrack

(59,592 posts) Thu Jun 20, 2013, 09:25 AM Jun 2013

In Maine, Tern & Puffin Dieoff Worsens; Scientists Link Disappearing Herring To Climate, Overfishing

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“We’ve seen a 40 percent decline of Arctic terns in the last 10 years,” said Linda Welch, a Fish and Wildlife Service biologist at the refuge. Arctic tern pairs in Maine have fallen from 4,224 pairs in 2008 to 2,467 pairs last year, the Fish and Wildlife Service said. Biologists at the Maine refuge are not sure whether herring sought colder waters elsewhere or went deeper, but they are no longer on the surface, from which Arctic terns pluck them. While other birds can dive deep for food, Arctic terns cannot.

“They’re not getting herring, so they bring butterfish that the chicks can’t swallow,” Welch said. “So they starve to death. You have thousands and thousands of chicks dying. It’s very sad.” On the Machias Seal Island, the largest tern colony on the refuge’s 50 islands, a shortage of fish prompted 3,000 pairs to abandon their nests in 2007. “They haven’t raised any chicks since,” Welch said.

Arctic terns arrive at the Maine islands after a month of flying from the Antarctic, about 470 miles a day — 14,000 total — low on energy, longing for a bite. If they lack food and energy, “they can’t keep the gulls off them,” Welch said. Gulls eat terns.

In the past two years, Welch said, biologists at the refuge went to the most productive foraging grounds where seabirds, whales and dolphin prey on herring, and spotted fishing trawlers. “When [the trawlers] come out, the whales and birds disappear, and you don’t see them again,” Welch said. “I think it’s hard to deny that they don’t have an effect on these birds.”

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http://www.washingtonpost.com/national/health-science/biologists-worried-by-migratory-birds-starvation-seen-as-tied-to-climate-change/2013/06/19/c04d8a74-d90d-11e2-a9f2-42ee3912ae0e_story.html?tid=ts_carousel

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In Maine, Tern & Puffin Dieoff Worsens; Scientists Link Disappearing Herring To Climate, Overfishing (Original Post) hatrack Jun 2013 OP

Same story in Puget Sound pscot Jun 2013 #1

pscot

(21,024 posts)

1. Same story in Puget Sound

Reply to hatrack (Original post)

Thu Jun 20, 2013, 10:47 AM

Jun 2013

Cherry point (site of an oil port and refinery) was historically the most productive herring spawning ground in the sound. The area has seen a 92% decline since the 70's, yet there's still a commercial fishery. Now the critters are beset by a non-native parisite.

We hypothesize that these population trends are the result of parasitic disease-related mortality, particularly among under-represented, older cohorts. Ichthyophonus hoferi, a protistan parasite historically associated with episodic mortalities to populations of Atlantic herring is currently ubiquitous among many herring populations on the west coast of North America. In Puget Sound prevalence of I. hoferi increases directly with herring age from 12% among 0yr cohorts to 58% among the under-represented, 6+ yr cohorts. Further, I. hoferi is highly pathogenic to immunologically naïve Pacific herring, causing 80% mortality 2 mo. after injection challenge. Considering that infections of I. hoferi among less than 10% of plaice captured near Scotland were estimated to result in annual mortalities of over 50%, we hypothesize that the infection levels detected among herring in Puget Sound can conservatively account for their recent high natural mortality rates.

http://wfrc.usgs.gov/fieldstations/marrowstone/ps_forage.html

All the forage fish are in trouble up here. Anchovy have all but vanished, and the scientific effort to understand these populations has been minimal. This is the base of the food chain for all the bigger animals in the sound. The proposed coal port on Bellingham bay will no doubt do wonders for the health of the Salish Sea.

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