Week 3: KML - Koch Key Site Characterization by Christian Fender and Larry Eichel (Larry J. Eichel)

Koch Key Site Characterization by Christian Fender and Larry Eichel

          To start off Cohort 2’s snorkeling at the Keys Marine Lab, we have Koch Key. Unique from the rest of the sites we visited this trip, Koch Key had a large amount of 3D structure as it was in fact an island composed of red mangroves on the outside ring and black mangroves on the inside. These mangroves trap sediment with their prop roots (i.e., reds) and pneumatophores (i.e., blacks) to hold the island together against the effects of wave action and tide changes. The roots of the mangroves also provide a habitat for fish that would not normally be found in such shallow water. There was a large amount of variation in depth depending on where in the Key we were. In general, there was a lot of seagrass (i.e., mix of turtle grass and manatee grass) around the island itself so the water was effectively about 4-5 feet deep. This grass was covered in a fine, silty sediment with a few hydroids we made sure to steer clear of. We saw a lot of smaller schooling fish like silversides in this area as well as a few needlefish.                                                                                                                    

          Leading to the island itself and passing through a small portion of the island was a deeper channel devoid of the seagrass that lined it. This channel was several feet deeper, and though visibility was only 5-6 feet and we couldn’t quite see the bottom, several species of larger fish (e.g., great barracuda, schoolmaster and grey snapper, angelfish, needlefish, sergeant majors, anchovy, snooks, porkfish, yellowfin mojarra, and pufferfish) could be found in the channel and where it met the mangrove’s roots. As far as invertebrates, there were many orange, purple, and blue sponges attached to the subtidal portion of the mangroves roots as well as some barnacles and oysters. Sea slugs, ragged sea hares, several spiny lobster, and various crabs were found between the grasses edge and the beginning of the mangroves. Two coral species (i.e., Solenastrea hyades and Siderastrea radians) and two anemones (i.e., Aiptasia and Condalactus) were also recorded.

A comprehensive, yet not exhaustive list of the species observed at Koch Key is listed below:

Aquatic Plants (i.e., mangroves and seagrasses)

• Rhizophora mangle
• Avicennia germinans
• Thalassia testudinum
• Syringodium filiform

Invertebrates (e.g., corals, hydrozoans, anemones, sponges, crustaceans, mollusks, etc.)

• Milleporina alcicornis
• Sertularella speciosa
• Solenastrea hyades
• Siderastrea radians
• Aiptasia spp.
• Condalactus spp.
• Elysia spp.
• Bursatella leachii
• Panulirus argus
• Portunus pelagicus
• Uca spp.
• Libinia emarginata
• Haliclona spp.
• Aplysina spp.

 Vertebrates

• Menidia menidia
• Strongylura marina
• Sphyraena barracuda
• Lutjanus apodus
• Lutjanus griseus
• Holocanthus spp.
• Abudefduf saxatilis
• Centropomus undecimalis
• Anisotremus virginicus
• Gerres cinereus
• Diodon spp.