Animals are more in touch with their environment than humans. As an example dogs and horses always seem to know a few minutes or days before we do that an earthquake is about to occur.
With the increase in the global temperature and associated climate altering implications, it only follows that animals would be the first be aware and acclimate to this new paradigm of their existence. It turns out that they have been responding to these changes for years and we weren’t paying attention.
As an example, on the west coast of the United States marine biologists are finding species of fish farther north than they ever have before. The abundance of many near-shore species of fish off southern California has declined since the temperature change of the mid-1970s. There has been a decline in the proportion of cooler water species and a decline in the numbers of 38 species common to the southern California coast. This overall decline is not limited to heavily fished species and appears correlated to a decline in plankton abundance. Similarly, seabirds that rely on fish as prey also have declined. The same is true in the North Sea. Researchers in England have found that 2/3 if the fished and non-fished species in the North Sea have shifted farther north or increased their depth distribution: http://www-unix.oit.umass.edu/~wfcon470/Perry%20et%20al%2005.pdf.
When I was on vacation in Colorado six years ago I talked with research biologists at the ‘Rocky Mountain Biological Laboratory’ (altitude 9,457 feet) and they agreed that from their observations there is a climatic shift taking place. Plant species were found at higher elevations than ever before, bears are coming out of hibernation earlier and the snow pack starts to build up later in the year. The local economic effect of a later snow pack is that the ski area in Modass`unt Crested Butte, Colorado installed millions of dollars worth of snow making equipment to supplement the weak snow pack early in the season. Like the Gulf Coast, they live and die by the tourist dollar.
Species commonly found in warmer water became more abundant from 1976 to 1987, especially during the 1982-83 El Niño. Climate changes could have an impact on many of California’s species and ecosystems. For example, between 1992 and 1996 the range of the bay checkerspot butterfly shifted 130 miles to the north and to higher altitudes as a result of climate changes.
Along the Gulf of Mexico, rock lobster and other species that are found in commercial quantities around the southern portions of Texas and Florida are migrating north to the cooler Gulf waters of Alabama, Mississippi, and the Florida Panhandle. According to NMFS landings data stone crab claws began to show up in Louisiana commercial landings starting in 1997 with 8,216 pounds landed. This has steadily increased to 50,772 pounds in 2000. If you happen to catch one in your crab trap or shrimp trawl break off the largest claw, throw the stone crab back and it will grow a new one. Rather nice of them don’t you think? The ability of Gulf fish to migrate north is limited by the lower salinity in the northern Gulf, which some Gulf species are unable to stand. Fishing in the Gulf could also be impacted if warmer temperatures continue to expand low oxygen conditions along parts of the northern Gulf Coast off Louisiana. Warmer water holds less oxygen.
The Canadian government has been doing fisheries surveys along the arctic edge of their nation for over 135 years. In the last 25 to 30 years their biologists have notice wholesale changes in the distributions of a number of common and widely disbursed species. Oceanographic work has correlated these changes in distribution with an increase in ocean temperature. A subtle change of half of one-degree might not be much to us but its effect is very pronounced on species that are low on the food chain. We might like to think that animals are driven by human-like emotions (anthropomorphic), when dealing with change they have only three reasons for doing anything: food, reproduction and survival. The species of fish that have altered their distributions are filter feeders. With the increase in water temperature phytoplankton and zooplankton are able to survive for longer periods of time and to reproduce in greater numbers than before and at higher latitudes. Satellite photos showing increased chlorophyll concentrations in the arctic have confirmed this. The fish are only moving to where the food is located. The lions are never far from the zebras.
The northern Gulf of Mexico is particularly sensitive to global climate change because of its susceptibility to sea level rise and its vulnerability to changes in tropical storm frequency and intensity. Several major North American watersheds drain through Gulf Coast estuaries, affecting estuarine hydrology and nutrient flow. If you want to know more about these changes type “Global climate change effects on fisheries” into your web browser.
Think Global – Act Local!