Organization: University of Maryland, College Park
References: <18NOV199221412504@trentu.ca>
Date: Fri, 20 Nov 1992 16:09:31 GMT
Lines: 45
In article <18NOV199221412504@trentu.ca> pstonge@trentu.ca (CMDR P.D. Keener) writes:
> G'day, I just read the recent postings regarding the state
>sanctioned killing of sharks (Hawaii???) after the attacks (was it one or
>two). Can't say I'm terribly happy about it.
(stuff deleted)
> On the other hand, what would the effects of a large scale tiger
>shark kill be in that area, from an ecological point of view. Clearly,
>the population dynamics of that area would be affected - particularly if
>this species of shark is a higher order carnivore. The potential release
>of predatory pressures on other organisms directly lower in the food chain
>should be a matter of concern. After all, what do these sharks normally
>eat? It follows that without these sharks, the population of these prey
>items could skyrocket, outstripping the food available to them, causing
>another peturbation. And of the higher order carnivores (what eats these
>sharks?). Without the tiger shark as a prey item, what alternatives do
>these other animals have? We all know that natural systems have a great
>resiliancy for peturbations in population, but this only goes so far... Is
>that mandated agency able to guarantee that a threat exists after all other
>possible steps have been taken to segregate the swimmers and the sharks?
>Has that agency performed an environmental impact assessment with the help
>of marine ecologists to ascertain the hazards involved with such a course of
>action? I'd really like to know...
As far as I know the only enemy of the tiger shark in Hawaii is man. But that
is not the issue that I want to address. The reproductive strategy of sharks
parallels that of humans. They have a long gestation time, bear live, fully
developed young that take years to mature sexually. They also have very few
young at a time. A species like that cannot easily weather large scale kills
such as the one planned in Hawaii. Compounding the problem is the search for the large sharks - the ones that are sexually mature and continuing the popula-
tion. It seems to me that the agency has *not* done any type of environmental
impact assessment. A problem with messing with shark populations is that their
dynamics are not understood well, except for the fact that they are very sensi-
tive to overfishing. I believe, once again, that when you enter the water
you take some risks, and it is not our right as human beings to go out there andtry to remove all the risks.
