Friday, 26 May 2017

Zane Grey Creek

By: Vanessa Jimenez and Emily Williams

Zane Grey Creek

On Tuesday, May 23rd, for our last stop of the day we visited Zane Grey Creek. This was located on the Atlantic side of Long Key, just a short walk from Keys Marine Lab. Zane Grey Creek is a natural mangrove tidal creek that has been dredged to gain access to Long Key Bight. We visited this site during low tide. The tidal creek had shallow water and no wave activity, with the exception of passing boats. These combined factors allowed for a lot of light penetration and low turbidity. The site was dominated by several primary producers including Rhizophora mangle, Thalassia testudinum, Laurencia, and Acetabularia. The natural structure from the Rhizophora mangle has created a haven for juvenile fish. Structure is an important part of marine ecosystems as it creates protection from predation, which is why this creek is a crucial nursery for many species. The Thalassia, Laurencia, and Acetabularia. also play an important role as primary producers in the habitat. The tidal influx of nutrients has impacted its success as a nursery. As the tide rises, nutrients from the Atlantic flush in, bringing extra nutrients. The availability of these extra nutrients increases primary productivity and in turn decreases grazing. Less grazing and limited wave action aids in the abundant growth of algae and sea grass. The sea grass in this creek were a lot larger compared to the sea grass observed at other locations, due to the high amount of nutrients. All of these factors play a pivotal role for the success of this ecosystem. 

Along with the primary producers, there were a large diversity of other species. These included sponges, corals, cnidarians, and juvenile fishes. The most abundant sponges in Zane Grey Creek were the loggerhead sponge, and the orange icing sponge. The only coral in the area was Siderastrea siderea. This is significant because the coral must out compete the abundant sea grass and algae. It is interesting because corals are usually found in areas where nutrients are depleted and this area was nutrient replete. The two cnidarians included Cassiopea cassiopea (upside down jellyfish) and Heteractis aurora (beaded sea anenome), which were both very abundant. The juvenile fishes in the creek were diverse. A few of the most common juveniles included Sergeant major, Lane Snapper, Slippery Dick and Bluestripped Grunt. Overall, Zane Grey Creek is a diverse tidal driven habitat that serves as a nursery for a wide variety of species.

Scarus guacamaia
Rainbow Parrotfish
Scarus iserti
Striped parrotfish
Abudefduf saxatilis
Sergeant major
Chaetodon capistratus
Foureye butterflyfish
Sphyraena barracuda
Great Barracuda (juvenile)
Lutjanus synagris
Lane snapper
Halichoeres maculipinna
Clown wrasse (juvenile)
Thalassoma bifasciatum
Bluehead wrasse
Halichoeres bivittatus
Slippery dick (juvenile)
Haemulon carbonarium
Caesar grunt
Haemulon sciurus
Blue striped grunt
Gerres cinereus
Yellowfin mojarra
Sphoeroides spengleri
Bandtail puffer
Heteractis aurora
Beaded sea anenome
Cassiopea cassiopea
Upsidedown Jellyfish
Mermaid’s cup
Caulerpa spp.
Halimeda spp.
Halodule wrightii
Shoal grass
Laurencia spp.

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