Lobsters and Salinity Question

[aquageek]

There have been some reports that the runoff from the flooding may cause a severe decrease in salinity level. This, in turn, would kill off a lot of lobsters.

Story:
http://www.thebostonchannel.com/weather/9250726/detail.html

Has anyone, over the past weekend, observed any lethargic or dead lobsters that would support this story? It just seems that, as divers can see what's going on below the surface, we can be of some value in reporting findings of aquatic conditions.

At any rate with lower salinity, maybe I can drop a pound or two of lead.

 

[krustykrab]

see the "Gloucester Weekend " thread - looks like there is some observation of dead lobsters last weekend.

The article does not make it sound too good for lobster hunting the next few weekends...?

Have you all seen / caught many keepers last weekend?

 

[johnnyseko]

Wow, good thread. Didnt think the rain would have that kind of impact! I havent been up that way in a bit. Sure doesnt sound good, though. It has been slim pickings all winter/spring....just when I was hoping they'd start to return...

 

[hlsooner]

Some interesting research from the University of New Hampshire

Responses to low salinity

Lobsters tend to avoid low salinity water. We have demonstrated this using several different behavioral assays (Jury et al., 1994a). Interestingly, we find that male and female lobsters differ somewhat in their aversive responses. Males appear to be less responsive, which might explain why there are more male lobsters the further one moves up into the estuary (Figure 2; see (Howell et al., 1999).
http://www.lobsters.unh.edu/neuro_physiology_behavior/neuro_physiology_behavior.html

 

[rubberduck]

Dove STB down the Cape Sunday and not much lobsters, dead or alive. Caught 2 small keepers and maybe saw 4 that were too small. It seems they are still out in deeper water so hopefully the ppoulation will be OK.

 

[Soggy]

I saw a whole bunch of live shorts just off of Salem...nothing dead.

As usual, I think the media is blowing things out of proportion.

 

[aquageek]

Is that a treadmill for lobsters I see in fig. 7? They actually devised a stress test for lobsters!

 

[hlsooner]

Yes, figure 7 appears to be a lobster treadmill. There is something we all want to put on the resume: invented a lobster treadmill!

 

[aquageek]

KrustyKrab -Thanks for the link to the Glouchester Weekend post. I forwarded the link to the Maine Dept.of Marine Resources. The reply:

Thanks for the note. This would not surprise me since they have limited ability to “escape” and can’t withstand much less than 20 ppt for more than a few hours. Considering that you got the rain even worse than we did, I can only imagine the impact. I recall a 12 inch rain in Portland, Me in 1998 that killed off all the organisms on pilings, piers, and stone walls. The freshwater lens was about 5 feet thick so shallow water animals (and plants) were in poor shape. Deeper, however, things were more healthy although as you point out in your website, there was a lot of settled material (silt etc.).

 

[mfalco]

Is that a treadmill for lobsters I see in fig. 7? They actually devised a stress test for lobsters!

It's a lobster powered belt sander