Tuesday, March 9, 2010

The Collapse

I got to thinking about the various species we have on island and realized a lot seemed threatened. Below is my summary of the what I have observed over the last 30-40 years. I would greatly appreciate other islanders inputs. COLLAPSED means a 90% sustained drop in population. I am ignoring land mammals (rats, muskrats, etc.) and insects. The nesting sea birds are my estimates of nesting birds at Sou'west Point at the end of May each year. Non-nesting populations are much lower. Are there other species I have forgotten? Some species are seen so rarely from shore, such as whales and porpoises, that I am not including them. My guesstimate for those species are significantly more during the late 70s and 80s than from the 60s, stable in the 90s, and slight decline in the 00s. Other inputs and observations welcome.



Species
1970s
population
2000s
population
Status
Comments
Nesting birds





Herring gull
10s of thousands
Low thousands/ hundreds
COLLAPSED


Black back gull
10s of thousands
Low thousands/ hundreds
COLLAPSED


Eider ducks
Thousands
Low hundreds
COLLAPSED


Cormorants
Dozens
Zero
COLLAPSED


Barn swallows
Hundreds?
Fewer?
?
Need more data
Bald Eagles
0
2-4 adults, chicks
Healthy
There may be second nest at
Eastern End
Pheasant
Dozen
Low Hundreds
?
Introduced in 60s. Summer 2009 did not appear to have any chicks. Racoon predation?







Sea Life





Herring
100s of tons caught
Zero
COLLAPSED
Purse seiner harvest
Harbor Pollock
1000s
Near zero
COLLAPSED
In harbor estimates
Mackerel
100s
Near zero
COLLAPSED
In harbor estimates
Barnacles
Common
Rare
COLLAPSED


Mussels
Common
Rare
COLLAPSED


Dog whelk (conch)
Common
Rare
COLLAPSED


Periwinkles
Common
Rare?
COLLAPSED


Urchins
Common
Rare
COLLAPSED
Over harvested in early 90s
Clams
Limited
?
?


Lobsters
100s of tons
100s of tons
Healthy
Harvest quantities
Crabs
Common?
Common?
?
Need more data
Starfish
Limited
Rare
?
Need more data
Harbor Seals
100s
100s
Healthy?
I think they have increased. Other comments?

3 comments:

  1. My greatest concern is that the gulls, eiders and cormorants aren't nesting because of the muskrats, Norway rats and now the new raccoon(s).

    Charlie Perakis

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  2. Thank you, Charlie for commenting.

    The bird situation is complicated. Certainly the land predators are part of the problem; we also had feral cats for a few years. The closing of the dumps on the mainland reduced the food supply for the gulls. The collapse of the fish and crustaceans are probably a stressor, too.

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  3. Rick,

    This is shocking. Hope you find a solution to bring back the bird populations.

    Mary

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