Tag: foreign ships

Mud Snail Slimes Into Great Lakes

A foreign invasive species is spreading to new areas. It’s a snail that could spread in huge numbers and compete with fish for food. The GLRC’s Mike Simonson reports:

Transcript

A foreign invasive species is spreading to new areas. It’s a snail that could
spread in huge numbers and compete with fish for food. The GLRC’s Mike
Simonson reports:


The New Zealand Mudsnail has made its way to Lake Superior. It had already
been identified in Lake Ontario. These snails become dense on a river or lake
bottom. Minnesota Seagrant Aquatic Species expert Doug Jensen says it’s like
having half a million in the space of a bathtub. They can squeeze out bottom
dwelling organisms that fish eat. Jensen says native fish eat New Zealand
Mudsnails, but the fish don’t digest them:


“They can pass through the guts of fish and potentially waterfowl and then
survive that situation and then breed in a new location, where ever they’re
deposited. They reproduce asexually. They produce clones of themselves; they
don’t need a male to establish a new colony.”


The snails are the latest on a long list of invasive species that have likely been
carried in by foreign ships.


For the GLRC, I’m Mike Simonson.

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States Seek to Tighten Ballast Water Laws

Port officials are wary about new state regulations intended to keep invasive species out of the Great Lakes. Several states are working on laws that would tighten restrictions on ballast water in foreign ships. The Great Lakes Radio Consortium’s Bob Kelleher reports:

Transcript

Port officials are wary about new state regulations intended to keep
invasive species out of the Great Lakes. Several states are working on
laws that would tighten restrictions on ballast water in foreign ships. The
Great Lakes Radio Consortiums Bob Kelleher reports:


Proponents hope to keep creatures like zebra mussels from getting
established in the Great Lakes. The non-native plants and animals arrive
in ship ballast water, carried from overseas ports.


Adolf Ojard is the Duluth Seaway Port Director. He says a state-by-state
approach to regulate ballast water is the wrong approach.


“We’re not the only area that is dealing with invasive species. Every
harbor and estuary around the world has a similar concern. It needs to be
dealt with on an international and world level, so that it can be a level
playing field for everybody out there that is involved in transportation.”


Michigan has passed new rules with stiff fines for ships with untreated
ballast water. Wisconsin and Indiana are expected to consider similar
rules; and Minnesota’s Attorney General says he’ll propose the
regulations this spring.


For the GLRC, I’m Bob Kelleher.

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Scientists Keep Tabs on Exotic Crab

  • Sightings of the Chinese mitten crab outside of its native habitat make some scientists uneasy that it will turn into an invasive species. (Photo courtesy of the California Department of Fish and Game)

Biologists are asking people to keep their eyes peeled for another potential invader into the Great Lakes. A Chinese mitten crab was found in the St. Lawrence River last fall. The Great Lakes Radio Consortium’s David Sommerstein reports:

Transcript

Biologists are asking people to keep their eyes peeled for
another potential invader into the Great Lakes. A Chinese mitten
crab was found in the St. Lawrence River last fall. The Great Lakes
Radio Consortium’s David Sommerstein reports:


Scientists aren’t sounding the alarm yet. One Chinese mitten crab found near Quebec City doesn’t constitute an invasion. But if they reproduce, the critters could spread quickly.


David MacNeill is a fisheries specialist with New York Sea Grant. He says one was found in Lake Erie in the 1970s, but didn’t proliferate. The mitten crabs spawn in salt water, so they don’t really threaten the upper Great Lakes. But the St. Lawrence River may be better habitat. Regardless, MacNeill says the discovery highlights problems with foreign ships exchanging ballast water before they enter the Great Lakes system.


“Inside ballast tanks on ships, they’re like giant tidal mud flats. When you empty all the water out, there’s this large mud layer. Some of these organisms can burrow into the sediment which is what the mitten crabs do.”


In January, the Coast Guard conceded its ballast discharge rules don’t always work. It said it must find new ways to keep foreign invaders out of the Great Lakes.


For the Great Lakes Radio Consortium, I’m David Sommerstein.

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