{"id":20364,"date":"2020-04-16T22:48:19","date_gmt":"2020-04-16T22:48:19","guid":{"rendered":"https:\/\/www.lifeandnews.com\/articles\/?p=20364"},"modified":"2020-04-17T12:15:36","modified_gmt":"2020-04-17T12:15:36","slug":"coastal-fish-populations-didnt-crash-after-the-deepwater-horizon-spill-why-not","status":"publish","type":"post","link":"https:\/\/www.lifeandnews.com\/articles\/coastal-fish-populations-didnt-crash-after-the-deepwater-horizon-spill-why-not\/","title":{"rendered":"Coastal fish populations didn&#8217;t crash after the Deepwater Horizon spill \u2013 why not?"},"content":{"rendered":"<p><a href=\"https:\/\/theconversation.com\/profiles\/f-joel-fodrie-990226\">F. Joel Fodrie<\/a>, <em><a href=\"https:\/\/theconversation.com\/institutions\/university-of-north-carolina-at-chapel-hill-1353\">University of North Carolina at Chapel Hill<\/a><\/em><\/p>\n<p>When the Deepwater Horizon oil spill released <a href=\"http:\/\/dx.doi.org\/10.1126\/science.1195840\">4 to 5 million barrels of oil<\/a> into the Gulf of Mexico in 2010, some early projections estimated that the toll on fisheries could reach <a href=\"https:\/\/doi.org\/10.1139\/f2011-171\">US$5-10 billion<\/a> by 2020. Chemicals in crude oil may affect fish and other marine creatures directly, through their toxicity, or indirectly by harming their food or habitat, and the effects can be immediate or long-term.<\/p>\n<p>I began conducting <a href=\"https:\/\/scholar.google.com\/citations?user=imy3JY0AAAAJ&amp;hl=en\">marine science research<\/a> in the northern Gulf of Mexico in 2006, and was immediately taken by the diversity of fishes, water bodies, habitats and economic sectors along the coast. This region is still home to my favorite saltwater environments \u2013 places like the <a href=\"https:\/\/en.wikipedia.org\/wiki\/Chandeleur_Islands\">Chandeleur Islands<\/a> off Louisiana, and Florida\u2019s <a href=\"https:\/\/en.wikipedia.org\/wiki\/St._Joseph_Bay\">St. Joseph Bay<\/a>.<\/p>\n<p>From 2006-2009, I worked with teams studying the ecology of fishes that inhabit the tidal salt marshes and underwater seagrass meadows of the northern Gulf. As the Deepwater Horizon spill unfolded, I shared many other people\u2019s deep concerns about the terrible human toll, and the ecological and economic damage to places like the sensitive shores where I had worked.<\/p>\n<p>Ten years later, though, there\u2019s some welcome good news. In our research, my colleagues and I have found that the Deepwater Horizon spill did not appear to cause significant oiling injury to coastal fish populations.<\/p>\n<p>It\u2019s a remarkable outcome, and a sharp contrast to the spill\u2019s effects farther from shore, where it <a href=\"https:\/\/oceanservice.noaa.gov\/news\/apr17\/dwh-protected-species.html\">killed thousands of marine mammals and sea turtles<\/a> and <a href=\"https:\/\/doi.org\/10.1098\/rsos.191164\">severely harmed life on the seafloor<\/a>. Why did coastal fisheries fare better? The answers are complex, and likely due to multiple mechanisms that we don\u2019t fully understand.<\/p>\n<figure><iframe loading=\"lazy\" src=\"https:\/\/www.youtube.com\/embed\/INknT3lkYys?wmode=transparent&amp;start=0\" width=\"440\" height=\"260\" frameborder=\"0\" allowfullscreen=\"allowfullscreen\"><\/iframe><figcaption><span class=\"caption\">Oiling along the Louisiana coast during the Deepwater Horizon spill, June 8, 2010.<\/span><\/figcaption><\/figure>\n<h2>Coastal fish populations hold steady<\/h2>\n<p>The Deepwater Horizon blowout started on April 20, 2010, and the well was not capped until <a href=\"https:\/\/www.epa.gov\/enforcement\/deepwater-horizon-bp-gulf-mexico-oil-spill\">July 15<\/a>. A month after the blowout, oil began encroaching on salt marshes and seagrass meadows across the northern Gulf, with inshore surface slicks persisting through August.<\/p>\n<p>This period overlapped with a seasonal peak in fish reproduction and immigration of larval fishes into estuaries \u2013 coastal zones where fresh and salt water mix, and underwater <a href=\"https:\/\/www.nps.gov\/subjects\/oceans\/seagrass-meadows.htm\">seagrass meadows<\/a> provide food and habitat.<\/p>\n<p>Using data from our pre-spill research \u2013 which sampled seagrass habitats in 12 estuaries from Louisiana to the Florida Panhandle \u2013 as a baseline, marine scientist Kenneth Heck and I resurveyed these same areas in the summer and fall of 2010. We found that the abundances of juvenile fishes such as drums, croakers, flounders and snappers <a href=\"https:\/\/doi.org\/10.1371\/journal.pone.0021609\">had not fallen below normal levels<\/a>. In fact, catch rates for many species were higher relative to 2006-2009.<\/p>\n<p>This pattern has held since 2011. Abundances of seagrass-associated fishes have continued to match pre-spill patterns across our study sites.<\/p>\n<p>Since these findings were published, we and other scientists have found similarly stable fish populations in diverse coastal areas hit by Deepwater Horizon oil. They include salt marsh-associated fishes in <a href=\"https:\/\/doi.org\/10.1007\/s12237-014-9890-6\">Louisiana<\/a> and <a href=\"https:\/\/doi.org\/10.1371\/journal.pone.0058376\">Alabama<\/a>, <a href=\"https:\/\/doi.org\/10.1080\/00028487.2015.1111253\">estuarine fishes throughout Mississippi Sound<\/a>, coastal <a href=\"https:\/\/link.springer.com\/article\/10.1007\/s00244-017-0374-0\">Gulf menhaden<\/a>, and <a href=\"http:\/\/dx.doi.org\/10.1371\/journal.pone.0108884\">shrimp in Louisiana bays<\/a>.<\/p>\n<p>Recently, I\u2019ve been working with a talented undergraduate student at the University of North Carolina at Chapel Hill to revisit commercial and recreational fishery harvest data going back to 2000. Those data, extending to 2017, also indicate remarkable stability in fish and shellfish harvests across the northern Gulf in the decade following the spill.<\/p>\n<figure class=\"align-right zoomable\"><a href=\"https:\/\/images.theconversation.com\/files\/328180\/original\/file-20200415-153318-1iovzfr.jpg?ixlib=rb-1.1.0&amp;q=45&amp;auto=format&amp;w=1000&amp;fit=clip\"><img src=\"https:\/\/images.theconversation.com\/files\/328180\/original\/file-20200415-153318-1iovzfr.jpg?ixlib=rb-1.1.0&amp;q=45&amp;auto=format&amp;w=237&amp;fit=clip\" sizes=\"(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px\" srcset=\"https:\/\/images.theconversation.com\/files\/328180\/original\/file-20200415-153318-1iovzfr.jpg?ixlib=rb-1.1.0&amp;q=45&amp;auto=format&amp;w=600&amp;h=450&amp;fit=crop&amp;dpr=1 600w, https:\/\/images.theconversation.com\/files\/328180\/original\/file-20200415-153318-1iovzfr.jpg?ixlib=rb-1.1.0&amp;q=30&amp;auto=format&amp;w=600&amp;h=450&amp;fit=crop&amp;dpr=2 1200w, https:\/\/images.theconversation.com\/files\/328180\/original\/file-20200415-153318-1iovzfr.jpg?ixlib=rb-1.1.0&amp;q=15&amp;auto=format&amp;w=600&amp;h=450&amp;fit=crop&amp;dpr=3 1800w, https:\/\/images.theconversation.com\/files\/328180\/original\/file-20200415-153318-1iovzfr.jpg?ixlib=rb-1.1.0&amp;q=45&amp;auto=format&amp;w=754&amp;h=566&amp;fit=crop&amp;dpr=1 754w, https:\/\/images.theconversation.com\/files\/328180\/original\/file-20200415-153318-1iovzfr.jpg?ixlib=rb-1.1.0&amp;q=30&amp;auto=format&amp;w=754&amp;h=566&amp;fit=crop&amp;dpr=2 1508w, https:\/\/images.theconversation.com\/files\/328180\/original\/file-20200415-153318-1iovzfr.jpg?ixlib=rb-1.1.0&amp;q=15&amp;auto=format&amp;w=754&amp;h=566&amp;fit=crop&amp;dpr=3 2262w\" alt=\"\" \/><\/a><figcaption><span class=\"caption\">Juvenile gray snapper, spotted seatrout, and pipefish sampled from Gulf of Mexico seagrass meadows.<\/span><br \/>\n<span class=\"attribution\"><span class=\"source\">Ben Raines<\/span>, <a class=\"license\" href=\"http:\/\/creativecommons.org\/licenses\/by-nd\/4.0\/\">CC BY-ND<\/a><\/span><\/figcaption><\/figure>\n<h2>Searching for causes<\/h2>\n<p>This lack of apparent oiling impact on fish populations is actually consistent with the aftermath of other oil spills, including <a href=\"https:\/\/doi.org\/10.1016\/S0025-326X(00)00075-8\">smaller-scale events in the Gulf<\/a> and others in <a href=\"https:\/\/doi.org\/10.1016\/S0025-326X(03)00161-9\">the Galapagos in 2001, near New York in 1990, and off Santa Barbara in 1969<\/a>. It even was true for the 1989 <a href=\"https:\/\/www.britannica.com\/event\/Exxon-Valdez-oil-spill\">Exxon Valdez spill<\/a>, which released 11 million gallons of oil in a prime fishing zone along Alaska\u2019s coast.<\/p>\n<p>In that infamous case, Pacific herring were the single major fishery stock that collapsed. Even that didn\u2019t occur until five years later, and <a href=\"https:\/\/doi.org\/10.1093\/icesjms\/fsm176\">the cause is still debated<\/a>. My own view is that some indirect, delayed instability related to oiling likely did impact those herring, although menhaden \u2013 an analogous fish in the Gulf of Mexico &#8211; have not shown signs of collapse following the Deepwater Horizon spill.<\/p>\n<p>Fishes\u2019 general resilience to oiling at the population level is even more surprising given what we know about how hydrocarbon exposure affects individual fish. In both lab experiments and fieldwork after Deepwater Horizon, scientists found that exposure to hydrocarbon compounds in oil and dispersants used to break down slicks during the spill harmed individual fish.<\/p>\n<p>Indeed, a review I conducted with other marine scientists and toxicologists in 2014 found that in about 99% of cases, individual fish exposed to concentrations as low as one part per billion of weathered oil and\/or Corexit dispersant from the Deepwater Horizon spill <a href=\"https:\/\/doi.org\/10.1093\/biosci\/biu123\">showed negative responses<\/a>. They included changes in genomic expression, physiological performance, reduced reproduction, abnormal behavior and lower survival.<\/p>\n<figure class=\"align-center zoomable\"><a href=\"https:\/\/images.theconversation.com\/files\/328179\/original\/file-20200415-153313-ygjcg2.JPG?ixlib=rb-1.1.0&amp;q=45&amp;auto=format&amp;w=1000&amp;fit=clip\"><img src=\"https:\/\/images.theconversation.com\/files\/328179\/original\/file-20200415-153313-ygjcg2.JPG?ixlib=rb-1.1.0&amp;q=45&amp;auto=format&amp;w=754&amp;fit=clip\" sizes=\"(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px\" srcset=\"https:\/\/images.theconversation.com\/files\/328179\/original\/file-20200415-153313-ygjcg2.JPG?ixlib=rb-1.1.0&amp;q=45&amp;auto=format&amp;w=600&amp;h=450&amp;fit=crop&amp;dpr=1 600w, https:\/\/images.theconversation.com\/files\/328179\/original\/file-20200415-153313-ygjcg2.JPG?ixlib=rb-1.1.0&amp;q=30&amp;auto=format&amp;w=600&amp;h=450&amp;fit=crop&amp;dpr=2 1200w, https:\/\/images.theconversation.com\/files\/328179\/original\/file-20200415-153313-ygjcg2.JPG?ixlib=rb-1.1.0&amp;q=15&amp;auto=format&amp;w=600&amp;h=450&amp;fit=crop&amp;dpr=3 1800w, https:\/\/images.theconversation.com\/files\/328179\/original\/file-20200415-153313-ygjcg2.JPG?ixlib=rb-1.1.0&amp;q=45&amp;auto=format&amp;w=754&amp;h=566&amp;fit=crop&amp;dpr=1 754w, https:\/\/images.theconversation.com\/files\/328179\/original\/file-20200415-153313-ygjcg2.JPG?ixlib=rb-1.1.0&amp;q=30&amp;auto=format&amp;w=754&amp;h=566&amp;fit=crop&amp;dpr=2 1508w, https:\/\/images.theconversation.com\/files\/328179\/original\/file-20200415-153313-ygjcg2.JPG?ixlib=rb-1.1.0&amp;q=15&amp;auto=format&amp;w=754&amp;h=566&amp;fit=crop&amp;dpr=3 2262w\" alt=\"\" \/><\/a><figcaption><span class=\"caption\">Members of the Coastal Waters Consortium sampling salt marsh fishes in Barataria Bay, Louisiana, May 29, 2014.<\/span><br \/>\n<span class=\"attribution\"><span class=\"source\">Anthony Vastano<\/span>, <a class=\"license\" href=\"http:\/\/creativecommons.org\/licenses\/by-nd\/4.0\/\">CC BY-ND<\/a><\/span><\/figcaption><\/figure>\n<p>So why don\u2019t these individual-level damages appear to show up as losses at population or community levels?<\/p>\n<p>First, since oiling in many estuaries was highly patchy, it\u2019s possible that many fishes, and some crabs and shrimp, were simply able to move away from it. Second, the fact that the spill affected many marine birds and mammals might have reduced predation on smaller fishes.<\/p>\n<p>The blowout also affected another key predator: humans. The spill response included large-scale fishery closures in the northern Gulf, which may have allowed for more reproduction by surviving adults in the spring and summer of 2010. This, in turn, would have showed up as greater abundances of fishes over the following months and years.<\/p>\n<figure class=\"align-center zoomable\"><a href=\"https:\/\/images.theconversation.com\/files\/328178\/original\/file-20200415-153334-1xei2jh.png?ixlib=rb-1.1.0&amp;q=45&amp;auto=format&amp;w=1000&amp;fit=clip\"><img src=\"https:\/\/images.theconversation.com\/files\/328178\/original\/file-20200415-153334-1xei2jh.png?ixlib=rb-1.1.0&amp;q=45&amp;auto=format&amp;w=754&amp;fit=clip\" sizes=\"(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px\" srcset=\"https:\/\/images.theconversation.com\/files\/328178\/original\/file-20200415-153334-1xei2jh.png?ixlib=rb-1.1.0&amp;q=45&amp;auto=format&amp;w=600&amp;h=473&amp;fit=crop&amp;dpr=1 600w, https:\/\/images.theconversation.com\/files\/328178\/original\/file-20200415-153334-1xei2jh.png?ixlib=rb-1.1.0&amp;q=30&amp;auto=format&amp;w=600&amp;h=473&amp;fit=crop&amp;dpr=2 1200w, https:\/\/images.theconversation.com\/files\/328178\/original\/file-20200415-153334-1xei2jh.png?ixlib=rb-1.1.0&amp;q=15&amp;auto=format&amp;w=600&amp;h=473&amp;fit=crop&amp;dpr=3 1800w, https:\/\/images.theconversation.com\/files\/328178\/original\/file-20200415-153334-1xei2jh.png?ixlib=rb-1.1.0&amp;q=45&amp;auto=format&amp;w=754&amp;h=595&amp;fit=crop&amp;dpr=1 754w, https:\/\/images.theconversation.com\/files\/328178\/original\/file-20200415-153334-1xei2jh.png?ixlib=rb-1.1.0&amp;q=30&amp;auto=format&amp;w=754&amp;h=595&amp;fit=crop&amp;dpr=2 1508w, https:\/\/images.theconversation.com\/files\/328178\/original\/file-20200415-153334-1xei2jh.png?ixlib=rb-1.1.0&amp;q=15&amp;auto=format&amp;w=754&amp;h=595&amp;fit=crop&amp;dpr=3 2262w\" alt=\"\" \/><\/a><figcaption><span class=\"caption\">Fishery closures during the Deepwater Horizon oil spill, June 21, 2010.<\/span><br \/>\n<span class=\"attribution\"><a class=\"source\" href=\"https:\/\/upload.wikimedia.org\/wikipedia\/commons\/2\/21\/Deepwater_Horizon_oil_spill_fishing_closure_map_2010-06-21.png\">NOAA<\/a><\/span><\/figcaption><\/figure>\n<h2>Short- and long-term disasters<\/h2>\n<p>Quantifying how ecosystems respond to broadscale impacts of something like a massive oil spill is extremely complex, especially when scientists can\u2019t test all of the possible explanations for what they find. Researchers can expose fish to oil and dispersant in a lab and see how they react, but they can\u2019t go out and dump oil in a marsh to replicate the spill, or replay the 2010 fishing season without spill closures.<\/p>\n<p>My decade studying the Deepwater Horizon oil spill has made me reconsider the relative impacts of \u201cpulse\u201d versus \u201cpress\u201d disturbances on coastal fishes. Pulse disturbances are big, one-time events like oil spills or hurricanes. Press disturbances are more gradual and have more insidious effects that accumulate over time. <a href=\"https:\/\/doi.org\/10.1111\/j.1365-2486.2009.01889.x\">Climate change<\/a>, <a href=\"https:\/\/doi.org\/10.1890\/150065\">coastal habitat degradation<\/a> and <a href=\"https:\/\/doi.org\/10.1080\/19425120.2013.786001\">intense fishing<\/a> are examples.<\/p>\n<p>Pulse disturbances tend to capture more headlines, but my emerging view is that press disturbances can have bigger negative effects over the long term. Therefore, I hope the 10th anniversary of the Deepwater Horizon disaster leads to a wider discussion of ways in which humans affect our coasts and oceans.<\/p>\n<p>[<em><a href=\"https:\/\/theconversation.com\/us\/newsletters?utm_source=TCUS&amp;utm_medium=inline-link&amp;utm_campaign=newsletter-text&amp;utm_content=expertise\">Expertise in your inbox. Sign up for The Conversation\u2019s newsletter and get a digest of academic takes on today\u2019s news, every day.<\/a><\/em>]<!-- Below is The Conversation's page counter tag. Please DO NOT REMOVE. --><img loading=\"lazy\" style=\"border: none !important; box-shadow: none !important; margin: 0 !important; max-height: 1px !important; max-width: 1px !important; min-height: 1px !important; min-width: 1px !important; opacity: 0 !important; outline: none !important; padding: 0 !important; text-shadow: none !important;\" src=\"https:\/\/counter.theconversation.com\/content\/133332\/count.gif?distributor=republish-lightbox-basic\" alt=\"The Conversation\" width=\"1\" height=\"1\" \/><!-- End of code. If you don't see any code above, please get new code from the Advanced tab after you click the republish button. The page counter does not collect any personal data. More info: https:\/\/theconversation.com\/republishing-guidelines --><\/p>\n<p><a href=\"https:\/\/theconversation.com\/profiles\/f-joel-fodrie-990226\">F. Joel Fodrie<\/a>, Associate Professor of Marine Science, <em><a href=\"https:\/\/theconversation.com\/institutions\/university-of-north-carolina-at-chapel-hill-1353\">University of North Carolina at Chapel Hill<\/a><\/em><\/p>\n<p>This article is republished from <a href=\"https:\/\/theconversation.com\">The Conversation<\/a> under a Creative Commons license. Read the <a href=\"https:\/\/theconversation.com\/coastal-fish-populations-didnt-crash-after-the-deepwater-horizon-spill-why-not-133332\">original article<\/a>.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>F. Joel Fodrie, University of North Carolina at Chapel Hill When the Deepwater Horizon oil spill released 4 to 5 million barrels of oil into the Gulf of Mexico in 2010, some early projections estimated that the toll on fisheries could reach US$5-10 billion by 2020. Chemicals in crude oil may affect fish and other [&hellip;]<\/p>\n","protected":false},"author":44,"featured_media":20365,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[1862],"tags":[4861,584,7945,753,6337,3817,7015,6012,235,7946],"_links":{"self":[{"href":"https:\/\/www.lifeandnews.com\/articles\/wp-json\/wp\/v2\/posts\/20364"}],"collection":[{"href":"https:\/\/www.lifeandnews.com\/articles\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.lifeandnews.com\/articles\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.lifeandnews.com\/articles\/wp-json\/wp\/v2\/users\/44"}],"replies":[{"embeddable":true,"href":"https:\/\/www.lifeandnews.com\/articles\/wp-json\/wp\/v2\/comments?post=20364"}],"version-history":[{"count":2,"href":"https:\/\/www.lifeandnews.com\/articles\/wp-json\/wp\/v2\/posts\/20364\/revisions"}],"predecessor-version":[{"id":20367,"href":"https:\/\/www.lifeandnews.com\/articles\/wp-json\/wp\/v2\/posts\/20364\/revisions\/20367"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.lifeandnews.com\/articles\/wp-json\/wp\/v2\/media\/20365"}],"wp:attachment":[{"href":"https:\/\/www.lifeandnews.com\/articles\/wp-json\/wp\/v2\/media?parent=20364"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.lifeandnews.com\/articles\/wp-json\/wp\/v2\/categories?post=20364"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.lifeandnews.com\/articles\/wp-json\/wp\/v2\/tags?post=20364"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}