{"id":177,"date":"2014-03-31T22:39:24","date_gmt":"2014-04-01T05:39:24","guid":{"rendered":"https:\/\/blogs.ubc.ca\/sumi\/?p=177"},"modified":"2015-06-12T22:27:11","modified_gmt":"2015-06-13T05:27:11","slug":"filter-cleaning-with-mussels","status":"publish","type":"post","link":"https:\/\/blogs.ubc.ca\/sumi\/2014\/03\/31\/filter-cleaning-with-mussels\/","title":{"rendered":"“Filter cleaning” with mussels"},"content":{"rendered":"

Mussels may be familiar to us on our dinner plates, steamed in butter and white wine sauce. In New York, it has become a city project<\/a>\u00a0 to study a related type of mussel called the ribbed mussel (Geukensia demissa<\/i>) in Long Island Sound. These mussels are the focus of a developing technology called \u201cbioextraction\u201d that might help clean up coastal waters.<\/p>\n

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Filter-feeding blue mussels, familiar to us on our dinner plates. Photo from Wikipedia.<\/figcaption><\/figure>\n

Ribbed mussels have some fascinating facts<\/a>\u00a0\u2013 they grow their shells in an annual cycle, so like counting tree rings, we can determine the age of a ribbed mussel by counting the number of ribs on their shells. They can survive in temperatures up to 45\u00b0C (a nice hot bath), and a\u00a0salinity<\/a>\u00a0tolerance range of 6ppt to 70ppt means they can live in freshwater-mixed dilute waters or in waters twice as salty as average seawater.\u00a0With their hardiness and ability to establish quickly, ribbed mussels\u00a0survived hurricane Irene and Sandy<\/a>\u00a0 and flourished while oyster species were hit hard and were almost wiped out in the affected regions.<\/p>\n

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Ribbed mussel by Joan Muller, from NOAA photo library.<\/figcaption><\/figure>\n
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Microscopic algae by NEON, from wikipedia.<\/figcaption><\/figure>\n

Nitrogen pollution is a growing problem in Long Island Sound as sewage, fertilizers, and other sources deposit nitrogen<\/a>\u00a0in those waters. Nitrogen exists naturally in the ocean, but too much of this creates a state called eutrophication<\/a>\u00a0\u2013 excess nutrients stimulate algal blooms<\/a>\u00a0 and hypoxia<\/a> (reduced oxygen) that makes the water less livable to existing organisms.<\/p>\n

Here is the logic<\/a> to using mussels. Mussels feed on small algae and plankton that naturally take up nitrogen from the waters. Removing nitrogen or tiny plankton directly from the water is difficult, but the mussels can do the job for us \u2013 they effectively collect tiny plankton and nutrients in their bodies, which leaves us to harvest the mussels themselves and as a result remove nitrogen from the waters.<\/p>\n

Mussels are like our water filters – pour some seawater through them and they filter out the plankton and algae (containing nitrogen), pumping out clean water. Afterwards, we change out the filter. Even better than filters, mussels can incorporate the excess nitrogen into their shells and meat.\u00a0This use of shellfish or aquatic plants with similar abilities to remove excess nutrients from the waters is called \u201cbioextraction<\/a>\u201d (See it explained in a diagram<\/a>).<\/p>\n

Why is this study so special? Bioextraction is the only method known<\/a>\u00a0to be able to remove nutrients after <\/i>they have leaked out to the rivers and oceans. So far, Long Island Sound has tackled various control methods to reduce the nutrient run-off from sewage treatment plants. In 2010, the Hunts Point Wastewater Treatment Plant has achieved an impressive 49% cut in their waste, changing an average of 22,000 pounds a day to 10,800 pounds per day, according to the New York Times<\/a>. However, they previously did not have a method to deal with the nutrients after it passed the plants.<\/p>\n

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Long Island Sound. The Bronx is above and Long Sound below. Photo by Doc Searls.<\/figcaption><\/figure>\n

This bioextraction project, carried out by a commercial shellfish farmer\u00a0Carter Newell<\/a>\u00a0and\u00a0supported by the U.S. National Oceanic and Atmospheric Administration<\/a> (NOAA), is one of the first attempts of bioextraction in the Bronx River region along with a project using seaweed bioextraction in the Sound. A previous study in Sweden<\/a>\u00a0 using blue mussels showed some promising results – mussels have been filtering water and taking up nutrients at a good rate. Although this may be less efficient compared to other filter-feeding organisms like the oyster, mussels can populate the area in dense layers, creating a huge aggregation of mussels. All the mussels combined can filter more nutrients than the oysters<\/a>\u00a0that could have lived in the same amount of space.\u00a0In the coasts of British Columbia, bioextractive technologies using other species including Asian scallop, sea cucumbers, and kelp are being explored (see more: Stephen Cross, \u201cSustainable Ecological Aquaculture (SEA) Systems: Building a Business Case for Bioextraction\u201d<\/a>).<\/p>\n

You might wonder, where do the mussels go after they are harvested? Ribbed mussels do not appear on our dinner plates – they are known to have an awful taste. However, scientists are exploring the potential use of harvested ribbed mussels <\/a>as fish feed, chicken feed, or fertilizer. Fertilizer is responsible for a large part of the excess nitrogen in coastal waters, so using mussels in the farms effectively returns the nutrients to its source.<\/p>\n

You can follow their progress<\/a>\u00a0as scientists closely monitor the impact of introducing ribbed mussels into the new environment and the native populations of mussels, algae, and plankton to evaluate whether this is an environmentally-responsible and effective solution against eutrophication.<\/p>\n

Additional note on mussel species –<\/p>\n

Mussels are also known as being invasive species in North America. For those of you who have learned about keystone species, you know that mussel populations can explode without a natural predator such as a Pisaster <\/i>sea star. The invasive mussels in BC<\/a> are actually a different species \u2013 commonly quagga mussels (Dreissena bugensis) and zebra mussels (Dreissena polymorpha).<\/p>\n","protected":false},"excerpt":{"rendered":"

Mussels may be familiar to us on our dinner plates, steamed in butter and white wine sauce. In New York, it has become a city project\u00a0 to study a related type of mussel called the ribbed mussel (Geukensia demissa) in Long Island Sound. These mussels are the focus of a developing technology called \u201cbioextraction\u201d that […]<\/p>\n","protected":false},"author":21657,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1637581,8940],"tags":[895537,873634,895536,174091,895538,561064],"class_list":["post-177","post","type-post","status-publish","format-standard","hentry","category-food-and-drinks","category-wildlife","tag-algal-blooms","tag-clean-water","tag-eutrophication","tag-filter","tag-long-island-sound","tag-mussels"],"_links":{"self":[{"href":"https:\/\/blogs.ubc.ca\/sumi\/wp-json\/wp\/v2\/posts\/177","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/blogs.ubc.ca\/sumi\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/blogs.ubc.ca\/sumi\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/blogs.ubc.ca\/sumi\/wp-json\/wp\/v2\/users\/21657"}],"replies":[{"embeddable":true,"href":"https:\/\/blogs.ubc.ca\/sumi\/wp-json\/wp\/v2\/comments?post=177"}],"version-history":[{"count":18,"href":"https:\/\/blogs.ubc.ca\/sumi\/wp-json\/wp\/v2\/posts\/177\/revisions"}],"predecessor-version":[{"id":483,"href":"https:\/\/blogs.ubc.ca\/sumi\/wp-json\/wp\/v2\/posts\/177\/revisions\/483"}],"wp:attachment":[{"href":"https:\/\/blogs.ubc.ca\/sumi\/wp-json\/wp\/v2\/media?parent=177"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blogs.ubc.ca\/sumi\/wp-json\/wp\/v2\/categories?post=177"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blogs.ubc.ca\/sumi\/wp-json\/wp\/v2\/tags?post=177"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}