Lack of Vegetation - Another Reason

[superdad]

The subject of the lack of underwater vegetation has become a topic ofssion between the anglers of the Bay of Quinte in the last number of years

 

The discussion has ranged from the lack of water clarity and water depth this summer to the carp in the weeds and the ice taking them out in the spring.

 

Laker John has found something in an article by Ted Takasaki and Scott Richardson in their "Night Shift Walleye" published on Walleye Central.

 

The interesting quote is: " Clear water is a common characteristic. Zebra mussels have made many lakes and reservoirs crystal clear. A lack of vegetation is another. Rusty crayfish have mowed thick weed beds down in many spots. "

 

The key to this is the mention of the Rusty Crawfish........and their mowing down weed beds.

 

Further looking at the Rusty Crawfish shows that they as an invasive species have and are causing much damage to the environment.

 

The Stop Aquatic Hitchhikers website says:

 

Why is the rusty crayfish considered to be a nuisance?

 

Competition with Native Species - Being an aggressive species, the rusty crayfish often displaces native or existing crayfish species. Ultimately, this could result in less food for fish. Crayfish are eaten by fish, but because of their thick shell relative to their soft tissue, the food quality is not as high as many of the invertebrates that they replace. Less food or lower food quality means slower growth, which can reduce fish survival.

Destruction of aquatic plant beds - When introduced, rusty crayfish reduce aquatic plant abundance and species diversity. This can be especially damaging in relatively unproductive northern lakes, where beds of aquatic plants are not abundant. Submerged aquatic plants are important in these systems for habitat for invertebrates (which provide food for fish and ducks), shelter for young gamefish, or forage species of fish, nesting areas for fish, and erosion control (by minimizing waves).

 

How do rusty crayfish affect recreational users?

 

Anglers - When rusty crayfish are introduced to a new system, the impacts are potentially devastating. However, because of the nature of these impacts, it takes time for anglers to directly feel these results. When a plant bed's diversity is decreased, a variety of effects take place. Generally, many species have difficulty acquiring food, which is necessary to grow and reproduce. Eventually, certain species decline, which ultimately disrupts the larger food web and effects all the species in an ecosystem including gamefish.

 

Macalester College website states:

 

The Rusty will invade the homes ofnative crayfish and has been known to eat fish eggs. Rusty crayfishreproduce speedily and efficiently with a typical females layinganywhere from 80-575 eggs. The Rusty will uproot and devour manyAquatic plants which provide a vital habitat for fish and otheraquatic animals, as well as preventing erosion.

 

The OFAH state in their InvasionSpecies.com website:

 

Rusty crayfish are omnivores so they will eat anything but prefer high protein foods. They feed on aquatic plants, benthic invertebrates (which include aquatic worms, snails, leeches and aquatic insects), decaying plants and animals, fish eggs, and small fish. They have a more aggressive nature than the native species in areas they are introduced to.

 

I believe these critters might be the reason that theweedbeds around Hay Bay have disappeared so suddenly.

 

Hope this opens our eyes to these Invsive Speciies and as I mentioned in an earlier post today, the existence of Spiny Water Fleas in Hay Bay and in the waters close to the Cement Plant near Picton.

 

Stay Tuned

[ecmilley]

thanks for the info, sure is intresting.

[hammercarp]

Thanks for the information. I did not know they are little armoured lawnmowers.

Edited September 8, 2008 by hammercarp

[cram]

have not been on the bay in a very long time -- curious.....how is the water clarity? Any algae issues?

[holdfast]

Well one thing is for sure. When they opened the locks and great Lakes to shipping, I don't think anybody was thinking about how it would change our Environment