marine environment

Invasive Species On Ships In Antarctica | Earth Wise

February 23, 2022 By EarthWise Leave a Comment

The Southern Ocean around Antarctica is the most isolated marine environment on Earth. Antarctica’s native species have been isolated for the last 15-30 million years. As a result, wildlife there has not evolved the ability to tolerate the presence of many groups of species.

New research by the University of Cambridge and the British Antarctic Survey has traced the global movements of all the ships entering Antarctic water and has found that Antarctica is connected to all regions of the globe via ship activity to an extent much greater than previously thought. Fishing, tourism, research, and supply ships are exposing Antarctica to invasive, non-native species that threaten the existing ecosystems.

In all, the research identified over 1,500 ports with links to Antarctica. From all these places, non-native species including mussels, barnacles, crabs, and algae attach themselves to ships’ hulls. The process is known as biofouling.

The greatest concern is the movement of species from pole to pole. These species are already cold-adapted. They may come on tourist or research vessels that spend the northern hemisphere summer in the Arctic before traveling south for the Antarctic summer season.

Mussels have no competitors in Antarctica should they be accidentally introduced. Shallow water crabs would introduce a new form of predation that Antarctic animals have never encountered before.

Current biosecurity measures to protect Antarctica, such as cleaning ships’ hulls, focus on a small group of so-called gateway ports. The new findings indicate that these measures need to be expanded to protect Antarctic waters from non-native species.

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Invasive species ‘hitchhiking’ on ships threaten Antarctica’s unique ecosystems

Photo, posted April 12, 2016, courtesy of NOAA’s National Ocean Service via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

The Hunt For Marine Plastic | Earth Wise

December 21, 2021 By EarthWise Leave a Comment

Estimates are that about 10 million tons of plastic enter the ocean every year. This is equivalent to a truckload of plastic being dumped into the sea every minute and the stuff is not easy to keep track of. Some of it ends up in the infamous ocean garbage patches. But overall, researchers only know what happens to about 1% of it.

The European Space Agency has decided to find out whether it might be possible to detect and track floating plastic in the oceans using satellite monitoring. Researchers have a variety of ideas about how best to do this and now the agency is testing some of those ideas.

The ESA maintains something called the Atlantic Basin Facility which is a 7000 square-foot tank equipped to simulate various types of waves and tidal currents. It is the largest facility of its kind in the world.

Researchers place plastic in the basin consisting of typical items found at sea, such as bags, bottles, marine nets and ropes, plastic cutlery, and Styrofoam balls. The plastic used in the study included material previously recovered from the sea through ocean cleanup campaigns. Multiple research groups from European universities used specialized instrumentation to monitor the basin from above. Techniques included radar remote sensing, something called GNSS reflectometry, and specialized optical instrumentation.

Initial results look promising in that under some circumstances teams received useable signals. It will take further analysis to determine the ultimate utility of space-based monitoring of plastic entering the ocean. Marine litter is a large and growing problem. Figuring out where it all is and where it is going is a necessary part of any solution.

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Hunting for marine plastic

Photo, posted March 24, 2017, courtesy of Holly Richards/USFWS via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

What’s Killing Orcas? | Earth Wise

January 18, 2021 By EarthWise Leave a Comment

With their characteristic tall dorsal fins and black and white color patterns, orcas are one of the ocean’s most iconic species. Measuring up to 32 feet long and weighing as much as 6 tons, orcas have one of the largest geographic distributions of any species. They live in all latitudes, in all oceans, from the Arctic to Antarctica.

While they are often referred to as killer whales, orcas are actually not whales at all. Orcas are the largest dolphin species and one of the most powerful predators on the planet.

But human interference has made life significantly more difficult for orcas in recent years. According to pathology reports on more than 50 orcas stranded over nearly a decade in the northeast Pacific and around Hawaii, the predators face a myriad of mortal threats. Many of those threats stem from human interactions.

Researchers from the British Columbia Ministry of Agriculture analyzed these orca pathology reports in a new study, which was recently published in the journal PLOS ONE,. Of 52 orcas stranded between 2004 and 2013, causes of death were determined for 42%. For example, one orca died after receiving a halibut hook injury. Two orcas died from the blunt force trauma of vessel strikes. While there was no singular common cause of death, the study found a common theme: human-caused deaths occurred in every age class – from juveniles to adults.

The researchers also note that humans aren’t just indirectly hurting orcas with things like lack of salmon or legacy toxins. Humans are also directly killing killer whales with boat strikes and fishing gear.

These findings will help establish a baseline of information to assess future orca conservation efforts.

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What’s killing killer whales?

Photo, posted July 5, 2009, courtesy of Rennett Stowe via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.