The Salem News
---- — We’ve long known that global warming would cause the sea levels to rise. But a related phenomenon is quickly becoming apparent along our coastline — a rapidly changing habitat for sea life.
This is a major change, one that is palpable and undeniable. Its impact is not entirely understood by marine biologists, but it is clearly bringing a fundamental shift to our coastal environment.
Fish and sea animals are far more sensitive to water temperatures than we are to air temperatures. Their habitats and migration patterns are tied tightly to the temperature of the water.
The changes became noticeable in local waters less than a decade ago, when some of our native species, such as mackerel and cod, started to show a change in their traditional habitats. They were not appearing in the places that they had been for decades, or they arrived unusually early in these locations. It was a sign of things to come.
In more recent years, particularly the past couple of years, changes have been more dynamic.
Certain species of fish, such as the bonita and the black sea bass, would never venture north of the south coast of Cape Cod. The ocean temperatures in our area were simply too cold for them. Last year, they were found slightly to the northeast of our local coastline in the Isles of Shoals area. This represents about a 100-mile northward change in their habitat area. This year, there have been some reports of these once-exotic fish showing up along the coast of Maine.
The local shrimp population, once a plentiful and reliable source of winter income for local fishermen, is no more. “Maine shrimp,” as the species is called, have migrated farther north.
And the New England Aquarium has reported a notable change in right whale habitat.
For many summers past, they gathered in sizable numbers in the Bay of Fundy, where they could find reliable quantities of the zooplankton that makes up most of their diet. This year, they have been scattered, which scientists believe is caused by a change in the location in the zooplankton — brought about by a change in ocean temperatures.
Closer to home, for the second year in a row, the North Shore of Massachusetts has been inundated with squid, a phenomenon also tied to water temperatures.
All of these changes are interrelated, happening all along our coastline.
As we worry about rising ocean levels eroding our coast and the possibility of more intense hurricanes, we should remember there are fundamental changes occurring under the waves, too. How they will change our future, and our local fisheries, is impossible to say. But it’s clear, based on what has happened over the past few years, that we will witness dramatic changes in the years to come.