As the weather has gotten colder we are once again faced with the not so pleasant prospect of coming down with the flu. The flu is a virus that seems to walk its way around the world every year making a lot of people’s lives miserable. With way the viruses’ have of changing very year one flu shot will not do it like it does for polio or the mumps – we need to have one every year. In the US alone the flu kills around 38,000 people every year. As much as we humans like to think of ourselves as special even right down to our diseases other animals also suffer from the wrath of viruses.
The northern gulf coast has been hit with a rash of virus induced fish kills over the last 20 years.
A big one hit in the spring of 1994 along the Texas coast. That fish kill was confined to the Sabine Pass area and was devoted almost exclusively to marine catfish. The two species most affected were the hardhead and the Gafftopsail catfishes. According to Texas Parks and Wildlife any other species killed were purely incidental and not directly due to the virus. In 1995 there were similar virus induced fish kills of marine catfish in the same area in Texas and in Tampa Bay, Florida.
In May 1996 millions of fish were killed by what was thought to be the same virus implicated in previous kills. Over 95% of the dead fish were hardhead catfish. The fish kill ranged from San Antonio Bay, Texas along the upper Gulf Coast to Crystal River, Florida.
This 2003 thousands of dead catfish washed up on the beaches of Dauphin Island and Fort Morgan. Tissue samples from the dead fish were collected and sent to the Alabama Department of Environmental Management for evaluation with the results expected back this week. Scientists suspect that the same virus that caused the fish kill in 1996 is the culprit.
While there is no direct evidence linking this virus outbreak to increased water temperatures from global warming it’s reasonable to speculate that if mammals, insects and fish are changing their ranges why not bacteria and viruses? As the planet warms the ranges of pathogens and parasites will change. The human experience with new pathogens is better documented than with animals. The American Indian’s tragedy is a good example. Popular history tells us that the Indians in North America were pushed out of the way by war with the white man and killing of the buffalo. In reality, 95% all the Indians were killed by the diseases the white man brought with him. Childhood diseases such as measles were devastating to the Indians. The worst included small pox and syphilis. It is reasonable to expect that as new animal pathogens find their way north or old ones find more fertile ground in waters warmed by global warming that we will see an increased impact on fish populations.
Think Global – Act Local!