{"id":66690,"date":"2008-06-27T00:00:00","date_gmt":"2008-06-27T00:00:00","guid":{"rendered":"https:\/\/www.uri.edu\/news-draft\/uncategorized\/climate-change-causing-significant-shift-in-the-species-composition-of-coastal-fish-communities-fishing-also-a-factor\/"},"modified":"2008-06-27T00:00:00","modified_gmt":"2008-06-27T00:00:00","slug":"climate-change-causing-significant-shift-in-the-species-composition-of-coastal-fish-communities-fishing-also-a-factor","status":"publish","type":"post","link":"https:\/\/www.uri.edu\/news\/2008\/06\/climate-change-causing-significant-shift-in-the-species-composition-of-coastal-fish-communities-fishing-also-a-factor\/","title":{"rendered":"Climate change causing significant shift in the species composition of coastal fish communities; fishing also a factor"},"content":{"rendered":"
\n\t\tInvertebrates and warm-water species increase, bottom feeders decrease<\/p>\n

\tNARRAGANSETT, R.I. \u2013 June 27, 2008 \u2013 A detailed analysis of data from nearly 50 years of weekly fish-trawl surveys in Narragansett Bay and adjacent Rhode Island Sound has revealed a long-term shift in species composition, which scientists attribute primarily to the effects of global warming.<\/p>\n


\n\tAccording to Jeremy Collie, professor of oceanography at the 溏心vlog免费B站\u2019s Graduate School of Oceanography, the fish community has shifted progressively from vertebrate species (fish) to invertebrates (lobsters, crabs and squid) and from benthic or demersal species \u2013 those that feed on the bottom \u2013 to pelagic species that feed higher in the water column. In addition, smaller, warm-water species have increased while larger, cool-water species have declined.<\/p>\n


\n\t\u201cThis is a pretty dramatic change, and it\u2019s a pattern that is being seen in other ecosystems, including offshore on Georges Bank and other continental shelf ecosystems, but we\u2019re in the relatively unique position of being able to document it. These patterns are likely being seen in estuaries around the world, but nowhere else has similar data,\u201d said Collie.<\/p>\n


\n\tResults of the research by Collie and 溏心vlog免费B站 colleagues Anthony Wood and Perry Jeffries will be published in the July issue of the Canadian Journal of Fisheries and Aquatic Sciences<\/a>.<\/p>\n


\n\tThe weekly trawl survey by 溏心vlog免费B站 scientists began in 1959 and continues to the present, making it one of the longest data sets of fish species composition available. The survey has recorded 130 species, though the analysis focused only on the top 25 species, which accounted for 96 percent of the total number of animals collected.<\/p>\n


\n\tCollie said that while most of the changes occurred slowly, an abrupt change appeared to take place in 1980 and 1981 when benthic species like winter flounder and silver hake declined and pelagic species including butterfish and bluefish increased. <\/p>\n


\n\t\u201cWe think there has been a shift in the food web resulting in more of the productivity being consumed in the water column,\u201d Collie explained. \u201cPhytoplankton are increasingly being grazed by zooplankton, which are then eaten by planktivorous fish, rather than the phytoplankton sinking to the bottom and being consumed by bottom fish. It\u2019s a rerouting of that production from the bottom to the top.\u201d<\/p>\n

\tCollie noted that the increase in the numbers of lobsters and crabs is a result of their taking advantage of the benthic habitat abandoned by the bottom-feeding fish species. <\/p>\n


\n\tOverall, the survey analysis found huge changes in the abundance of some species. Butterfish and bluefish, for instance, have increased in abundance by a factor of about 100 times while cunner has decreased by almost 1,000 times.<\/p>\n


\n\tThe analysis also found that while the total number of fish caught in each trawl increased over time, peaking in the 1990s, the size of those fish decreased. <\/p>\n


\n\t\u201cWhile we\u2019re catching more fish now, we\u2019re also catching smaller fish,\u201d said Collie, \u201cand that corresponds with how the preferred temperatures of the fish here have changed. The fish community now is dominated by warm-water adapted species compared with what we started with, and fish that live in warmer water are smaller.\u201d<\/p>\n


\n\tCollie added that fishing may also be a factor in the decline in fish size, since fishing removes the largest individuals from a population while leaving the smaller ones. However, he believes that climate is \u201cthe dominant signal.\u201d Sea surface temperature in the area of the trawls has increased by 2 degrees Centigrade since 1959, and the preferred temperature of the fish caught in the trawls has also increased by 2 degrees C.<\/p>\n


\n\t\u201cThat seems to be direct evidence of global warming,\u201d he said. \u201cIt\u2019s hard to explain any other way.\u201d<\/p>\n


\n\tThe shift in species composition also correlates with the winter North Atlantic Oscillation index and with chlorophyll concentrations, which declined by 50 percent, both of which are related to warmer sea temperatures.<\/p>\n


\n\tWhat do these changes mean for the future of Narragansett Bay?<\/p>\n


\n\t\u201cOur overall prediction is that Narragansett Bay is soon going to resemble estuaries to the south of us \u2013 Delaware Bay, Chesapeake Bay \u2013 so we\u2019ll experience what they are experiencing now,\u201d Collie said. \u201cIt will continue to get warmer and attract more southern species, such as blue crabs. Species that couldn\u2019t complete their life cycle here before may be able to do that now.\u201d <\/p>\n<\/div>\n","protected":false},"excerpt":{"rendered":"

Invertebrates and warm-water species increase, bottom feeders decrease NARRAGANSETT, R.I. \u2013 June 27, 2008 \u2013 A detailed analysis of data from nearly 50 years of weekly fish-trawl surveys in Narragansett Bay and adjacent Rhode Island Sound has revealed a long-term shift in species composition, which scientists attribute primarily to the effects of global warming. […]<\/p>\n","protected":false},"author":2,"featured_media":66693,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":"","_links_to":"","_links_to_target":""},"categories":[2],"tags":[],"class_list":["post-66690","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-archives"],"acf":[],"_links":{"self":[{"href":"https:\/\/www.uri.edu\/news\/wp-json\/wp\/v2\/posts\/66690","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.uri.edu\/news\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.uri.edu\/news\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.uri.edu\/news\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.uri.edu\/news\/wp-json\/wp\/v2\/comments?post=66690"}],"version-history":[{"count":0,"href":"https:\/\/www.uri.edu\/news\/wp-json\/wp\/v2\/posts\/66690\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.uri.edu\/news\/wp-json\/wp\/v2\/media\/66693"}],"wp:attachment":[{"href":"https:\/\/www.uri.edu\/news\/wp-json\/wp\/v2\/media?parent=66690"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.uri.edu\/news\/wp-json\/wp\/v2\/categories?post=66690"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.uri.edu\/news\/wp-json\/wp\/v2\/tags?post=66690"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}