The Skidaway Institute of Oceanography is in the middle of a bracing, and quite popular, springtime series of lectures by some of its esteemed scientists.
Next up is "Living with the Ocean," featuring Dr. Clark Alexander, who will speak on barrier island erosion, and biodiversity expert Dr. William Savidge. The program happens twice: Monday, April 20, at the Coastal Georgia Center on Fahm St. downtown and again Thursday, April 23, in the library auditorium at Skidaway Institute. Both of the free programs begin at 7 p.m.
We spoke to Dr. Savidge about his specialty, biodiversity in marine life, and why you should care about it.
What types of diversity are you really talking about here?
Bill Savidge: It's about diversity, but not just at species level but at higher taxonomic level. As human beings we can think about crabs in the ocean and fish in the ocean, but really most of the very basic kinds of life live in the ocean. Most people don't think about it at that level, so I'd like to introduce that.
As a scientist, are you going to try and steer clear of the socio-political ramifications of diversity loss or just give the facts?
Bill Savidge: I will certainly outline some arguments about why scientists care about diversity and why the public should be aware of issues of diversity as well. You open up a newspaper or look online and you do see a lot of talk about diversity this and diversity that, and for a lot of people there's sort of a shrug of the shoulders and a so what. I want to address why one might care about losing biodiversity.
There's a lot of ocean out there. Is diversity loss worse the closer you get to the coast and human habitation?
Bill Savidge: Probably not an easy question on a couple of levels. One is that once you get away from immediate coast our knowledge of what's actually there becomes much more limited. Certainly problems are going to be greatest near coast because that's where the forces that are leading to loss of diversity are applied more vigorously. Pollutants, habitat loss.
Overall I'd say issue of absolute diversity loss - as in it's gone, extinct - is probably less severe in the oceans than on land. Species range tends to be larger in the ocean. You can't completely destroy the entire coastal realm of the eastern seaboard of the U.S., but you can bury one mountain valley that holds a specific species. Terrestrial ranges tend to be more limited and our ability to impact those environments tends to be more significant. But that doesn't mean we aren't reducing some marine populations to irrelevance. For example, we have essentially eliminated as a component of the ecosystem, cod from the Grand Banks. We've not driven cod to extinction but they are terribly low on numbers.
There was something in the news a few weeks ago about the South Atlantic Fisheries Commission about the extent of fishing down populations of red snapper on our coastal shelf. They're maybe one percent of what they were 50 years ago. They're not going extinct - yet - but they're suffering.
How much of this is immediately fixable, like halting fishing in certain places, and how much of it is due to global warming?
Bill Savidge: Speaking outside expertise here, but probably in terms of fisheries the issue is almost entirely one of overexploitation of stocks rather than effects of climate change. Isolated populations of fish may depend on rivers, like salmon or sturgeon. Then maybe climate change will be part of their problem. Mostly for fisheries it's a human problem.
Are you seeing a lot of adaptive behavor by marine life, fleeing the effects of human fishing?
Bill Savidge: Saw an article a couple of weeks ago that suggested that just like on land some fish are moving their ranges northward in response to temperature changes. So they will presumably be interacting with indigenous species as they move, which may lead to unforeseen consequences.
Chain reactions we aren't necessarily seeing but could imagine happening, and they are chain reactions for which we're not able to predict the consequences. If tuna move to Greenland, what happens? A silly hypothetical, but we have no idea.
Living with the Ocean
Drs. Clark Alexander and William Savidge speak on diversity and habitat loss.
When & Where: 7 p.m. April 20 at the Coastal Georgia Center, Fahm Street downtown, and 7 p.m. April 23 at the library auditorium at the Skidaway Institute of Oceanography.
Cost: Free and open to the public.