There has been a lot of news about the devastation that the oil gusher is having and will have on the marine life of the Gulf of Mexico. The face of that devastation takes the form of oil soaked birds and the bodies of dolphins and turtles. There is also a commonly repeated statement that the real damage will be invisible, billions upon billions of larval fishes and other micro-organisms that will perish in the water column when oil passes through it. This carnage has no face. Below I will talk a bit about the diversity of life in the Gulf and show some photos of local denizens that I took yesterday.
According to an exhaustive recent summary* of the biodiversity of the Gulf of Mexico there are over 15,000 species of marine life that are known from the Gulf. About 10% of those 15,000 species are endemic to the region meaning that they are not known to occur anywhere else. It should be noted that this list does not include any species of bacteria and that many more species remain undescribed. Also some species considered endemic undoubtedly occur outside the gulf but have simply not been found there yet. Of the total species, just over 2000 are vertebrates with the vast majority of those being fishes. The turtles, dolphins, whales, and birds are just the tip of the biological iceberg, probably representing less than 1% of the species in the gulf.
On Sunday I visited St. Andrew's State Park near Panama City. I spent a couple of hours snorkeling there and took a bunch of pictures. Kossack and Panama City resident Kristina40 has a great diary about St. Andrew's. Oil came ashore in the area about three weeks ago for a fairly short time (I was out of the country at the time and don't know all the details). Since that time the wind has blown the surface oil quite some distance to the west.
St. Andrew's is famous (at least in the circles I frequent) as a great place to go snorkeling in northern Florida. Most of our coastal areas are beaches or salt marsh. The rock jetties that line St. Andrew's pass, the passageway between the Gulf and St. Andrew's Bay, represent an 'island' of rocky, reef habitat.
Many marine animals have pelagic larval stages. This means the offspring travel long distances, floating in the open ocean. This is true for organisms such as many crabs, clams, sponges, corals, sea urchins, and so on. And fishes.** The loop current brings many of these organisms to the rocks of the St. Andrew's jetty. Most of you have probably heard of the loop current because of the danger that oil will get caught in it and carried south to the Florida Keys. In this context we are talking about the second half of the 'loop'. The first half carries water from the vicinity of the Yucatan peninsula up to the northeastern gulf. By doing so it is transporting the larval stages of many tropical reef organisms. If you look at the linked map above you will notice that the northern part of the loop intersects local currents leading more or less straight towards Panama City. The rocks of St. Andrew's are a suitable habitat for these tropical species (at least in the summer) and you can see quite a few fish species there at the far northern edge of their ranges.
Unfortunately Sunday was not an ideal day for snorkeling. The water was moderately rough which reduced visibility. Visibility was essentially zero on the ocean side of the jetty. So I snorkeled in the lagoon and along the channel side of the jetty. I took over 300 pictures, most of which were completely worthless. Don't expect anything like a Haole in Hawaii diary here. I'm just a guy with a point and shoot and underwater housing taking underwater photos for the third time in his life. But hopefully they will give you a feel for what is at risk.
Yesterday was not a great day for seeing the more exotic fish species or for seeing the larger fish species which are mostly out near the end of the jetty where I didn't go. However It was a great day for seeing lots and lots of individual fish. There were huge schools of small fish all along the rock face and over the sand. I hadn't seen this before but those with more experience say they have. The schools were so dense you couldn't see any light through them at all. I can safely say I have never seen so many fish in one day in my life before.
Here is a closeup showing the world these schooling fish live in. I would find it very disorienting.
There were of course many other fish there as well. The most brilliant were the juvenile Beau Gregories, a kind of damsel fish. Like many reef fishes these undergo dramatic color changes as they age.
Here is another common northern damsel fish, the sergeant major.
How many fish are in this picture?
How about in this close up? I count seven
They are some species of blenny. They blend in well with their surroundings but if you look closely they are everywhere on the rocks.
In the foreground is a species of wrasse with the rather unfortunate common name of Slippery Dick. The fish in the background include a Doctorfish which is a kind of tang and what I think are Roundspot Porgy although I am not positive.
Life a number of wrasse species and other reef fishes the slippery dick is a fish that can change sex. In this case they start out as females and become males later in life.
Here are some other organisms besides fishes.
Sea Urchins
Snails and Barnacles
And some interesting algae
Surfacing briefly I spotted something close by
Last time I was snorkeling there I discovered that the birds often didn't react to human in the water as they would to someone on land. I took advantage of this to get closer.
I moved across a low spot in the rocks to swim into the shallower water of the 'Kiddie Pool'. Lots of schooling fish in there as well.
There were also lots of rocks with lush algal growth to graze on
And a few new fish like this striped grunt
And this stingray (enhanced to make it show up against the sand
So if you go to the pool make sure you are careful where you step.
So to come back to my original point. Most of these animals (and algae) will have arrived at the jetty as planktonic organisms from further away. Larger adult animals will be more resistant to the effects of oil - tiny ones less so.
*The source is Tunnell, J., D. Felder, and S. Earle. 2009. "Gulf of Mexico: Origin, Waters and Biota. Volume 1: Biodiversity." Published by Texas A&M University Press. The link provided above goes to Google books which provides part of the text.
**Before someone points out my 'mistake' I will point out that the plural of fish is fishes when you are talking about multiple species.