Wednesday, July 17, 2013


Terry Baurley
Lovell’s Island

One of the explanations for what seems like an area that is more affected by invasive species is the approximated to the Blackrock channel. The proximity brings the ships closest to shore and it’s one of the furthest islands out, I would hypothesize that the other islands within the harbor are not nearly as affected. It’s even possible that the original place where ships have traditionally emptied ballast water in that area. One of the things that I noticed about the container ships were in the process of being tugged out to sea by tugboats which suggest that it might be narrow, shallow and difficult to navigate. It’s possible that they may empty their ballast just prior to entering the Black Rock Channel in an effort to lighten the load, and the tide may have carried concentrated amounts of water from the ballast towards the island.

Several of the shells that were found on the metal cover on the beach. According to the Boston Harbor Islands at Harvard entomology they seem to suggest that the shells might be Brown lipped snail, the specimen we examined was approximately half an inch with the top half missing yet when I look back at the blog from previous visits I get conflicting data, in a posting by Sabrina Liu on 8/3 2010. There are two different types on the island, which are the white lipped snail, the other one is a Brown lipped snail. The Brown lipped snail was actually introduced in 1857 by Dr. Binney by accident and is now found in fifteen states. The defining shape of the shell’s opening has a very distinctive much lighter shell and no color at the opening of the shell. But when comparing the two shells the Brown lipped snail shell is much larger. The similar one from metal cover does not seem to fit the white lipped description.

I actually have to go with the identification as a juvenile terrestrial snail. Daniele Wesson in her blog post on July 26, 2012 identified the snail as a terrestrial snail and agree.The reason that I believe that this indeed is a juvenile terrestrial snail is that at the field Museum of Natural History by Jochen Gerber says that to confirm the identification that you confirm by “break the window of the body whorl that you’ll see a columellar fold.” Which explains why the top of the shell looks like it’s been cut off.The explanation of the snails being found on the beach, makes sense because these snails are usually found at the high water mark. I’m not sure that a bird dropping it from the heights is the correct hypothesis because the bird suggested was a song thrush. According to the Audubon and Peterson’s bird guide books, the song thrush, does not inhabit any part of the United States, song thrush birds are actually from England and may have a range as far as Ireland, unless bird was off course during a storm he would be highly unlikely that you would find them here.

Another confusing things that I noticed was when we started to catch the black sea bass in the field guide to nature of New England by Ken Kaufman and Kimberly Kaufman states that black sea bass are mostly found in shallow water often around docks, jetties, piers and other structures What is confuseing here is that the water was not all that shallow or nowhere near any piers or any underwater structure.
One of the other important pieces of information while researching the species thta we incountered is how important rock weed is to the health of the community, the reason it is used is because “primary producer converting inorganic nutrients into organic biomass using the energy of the sun.” Some of the reasons how rockweed is important to the environment is that it’s harvested as a supplement used in multiple products. It is also a shelter for all types of life forms especially lobsters and periwinkle. But it also  has the ability to remove trace elements and pollution from the water. Very similar to mussels, oysters and clams as far as filtering and cleaning the water. One of the biggest problems with managing this resource is like all resources  it need to be properly managed by partially cut rather than completely cut so that it’s there for future generations.

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