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Vital Information (08-11-10)

In Matt, Scallops, Vital Information on August 26, 2010 by Two Barbers Tagged: , , , , , , , ,

Scallops are hermaphroditic.

Most of the 300 species are protandrous, which means that during spawning they release gametes in the order of male first, female second (if you are not familiar with the term ‘gamete’ it simply refers to either of the implicated cells in sexual reproduction; i.e., ovum in females, sperm in males). However,Argopecten irradians, better known as the Bay Scallop, displays variation in its reproductive behavior, depending on each individual irradian, although it usually follows suit with the rest of its Pecten brothers and sisters.

Spawning usually takes place sometime after the first year and is influenced by physical conditions such as wave size, lunar phases, currents, chlorophyll concentration (more chemical), and, most effectively, water temperature, more specifically, by both increases or decreases depending on locale.

The particular sub-species of bay scallop that inhabits the Long Island estuaries in the Peconic and South Shore bays, Argopecten irradians irradians, tends to spawn in the months of June and July when the temperature of the water rises to about 15oC.

Over the last 25 years, the bay scallop population has been decimated throughout the Long Island water systems.

In the years leading up to the mid-eighties, 25% of the national consumption (around 350,000 lbs.) was supplied by the Peconic Watershed, including 700,000 lbs. in 1974, until ’85 when a blooming alga, Aureococcus anophagefferens, referred to as “brown tide” swept through, throwing off the ecological balance.  Subsequent waves of brown tide in ’87 and ’95 left the area’s output reduced to a diminutive 1%, between 3,000 and 6,000 lbs.

Although the bay scallop is gametecally prolific, one being capable of producing 5 million eggs, they only live a span of 18-22 months; meaning they spawn once, which leaves a single shot for semination. And since the male gamete is not injected directly, but rather is floated out, the thinner the crowd, the less chance they will have fertilize. (The can send it right back if they want to.)

You can see how it gets more complicated and interconnected.  Less larvae means less juvenile scallops, which means less adults, all of which are reduced by the depletion of their protective eelgrass habitats, also caused by the brown tide, as well as the reduction of the organisms it supports that also support it, etc. etc. etc…

There are a lot of conservation groups working on this problem.

For more vital information on Scallops, please refer to our blog from Wednesday July 21st and check back in a few weeks

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