Keys Marine Lab, Old Sweat Bay: Week 2

By: Kayli Morgan and Sarah Boullard

Our third stop on Monday, 05/22/2017, was Old Sweat Bay. Closer to the Atlantic we had clear and shallow water that opened into a canal for boats. When we went out it was partially cloudy with overlaying sunshine. The tide was going out, resulting in a strong westward current. We started snorkeling over the shallow bank and worked our way towards the canal.

            In our location we saw few hard corals, including Porites furcata, Cladocora arbuscula, Siderastrea radians, and Manicinia areolata. But the old corals that made the bottom of the bay was primarily dominated by macroalgae such as Avainvillea spp, Udotea spp, Caluerpa paspaloides, Caluerpa prolifera, Halimeda incrassata, Halimeda tuna, and few other green alga. Our location had clear water with high light attenuation which is why we saw more green algae opposed to red or brown algae, because green alga depend on the light to go through photosynthetic processes.

            We saw quite a few invertebrates such as Isostichopus badiontus, the three-rowed sea cucumber, Pagurus pollicaris, the flat claw hermit crab, Triplofusus gigantenus, the horse conch, Lobatus gigas, the queen conch, Menippe mercenaria, the Florida stone crab, and a species of special interest, Diadema antillarum, the long spine urchin. Diadema antillarum is almost always found on the Atlantic side, however we saw two large urchins at Sweat Bay, which is on the Gulf side. This species is ESA listed and there are current restoration projects underway to try and increase the urchin’s numbers and seeing this species on the Gulf side is a good indication that the restorations efforts are proving effective.

Diadema antillarum, the long spine urchin

 Isostichopus badiontus, the three-rowed sea cucumber

            We did see a loss of both coral and algae abundance as we neared the canal. This is probably a result of the continual dredging efforts needed to keep this
channel navigable by boat. We saw more soft corals and algae that moved with the currents.

Species List
Porites furcata	-
Cladocora arbuscula	-
Siderastrea radians	-
Manicinia areolata	-
Avainvillea spp	-
Udotea spp	-
Caluerpa paspaloides	-
Caluerpa prolifera	-
Halimeda incrassata	-
Halimeda tuna	-
Rhipocephalus spp	-
Crustose spp	-
Thalassia testudinum	-
Thalassia hemprichii	-
Halodule wrightii	-
Syringodium isoetifolium	-
Spheciospongia vesparium	Loggerhead sponge
Isostichopus badiontus	The three-rowed sea cucumber
Pagurus pollicaris	The flat claw hermit crab
Triplofusus gigantenus	The horse conch
Lobatus gigas	The queen conch
Menippe mercenaria	The Florida stone crab
Diadema antillarum	The long spine urchin
Pareques acuminatus	High-hat
Sphoeroides spengleri	Ban tail puffer
Serrauns tabacarius	Tobacco fish
Halichoeres bivittatus	Slippery dick
Coryphopterus glaucofraenum	Bridled goby
Aetobatus harinari	Spotted eagle ray