Introduction

Introduction

Uca minax is a fiddler crab species found along the United States's east coast, as well as in the Gulf of Mexico. They are easily differentiable from other fiddler crab species due to their red joints, giving them their common name: a red-jointed fiddler crab. Males have one major claw on either side of their body, which can grow to be up to fifty percent of their body mass, and a regular-sized claw on the other side, while females have two normal-sized claws (Bethany Fisher). Fiddler crabs live in coastal wetlands in the intertidal regions of the coast, meaning seawater from the ocean periodically floods their habitat based on the high and low tides. Salt marshes are broken down into the high marsh, midshore, and low marsh. The low marsh is the least salty of the three portions; this is due to the fact that is most always submerged by water, lessening the amount of evaporation occurring. The Uca minax mostly inhabit this region of the wetlands due to its low salinity (Susan Woodward).

 

It is known that fiddler crabs are considered indicator species, meaning that their population fluctuates easily with changes in their environment (Wenner). Fiddler crabs burrow into the sediment for protection and to mate in, which aerates the soil and moves the sediment and nutrients around, maximizing their availability for other organisms (Subhasish Chatterjee). This, in return, increases the productivity of their habitat. Fiddler crabs are very sensitive to contaminants, such as insecticides and fertilizers, that come from rain runoff and river drainage. Should the amounts of these increase, the population of the fiddler crabs in the area would decrease. Because of the fact that these contaminants are biomagnified as one moves further up the food chain, meaning that these pollutants are found in much higher quantities in bigger predators than in organisms such as primary producers and primary consumers, this form of pollution affects the entire ecosystem (Wenner). With this being said, in order to see clearly whether or not the ecosystem is thriving, it is easy to look at the stability of the fiddler crab population.

 

The fiddler crabs were counted at the site during new and full moons at low tide during their breeding season, in order to ensure as many crabs as possible were seen. They must be counted during the breeding season because outside of this season, they remain inside their burrows, unable to be counted. Keeping accurate data of the population of the Uca minax fiddler crab species makes it possible to see the trends in the future population more easily.
 

Many limitations must be taken into consideration in order to fully understand the scope of this project. During data collection, the weather being different could affect the amount of crabs counted on a given day; should it be cold, windy, or rainy out, then the fiddler crabs may be inclined to go into their burrows, preventing them from being counted. As the breeding season progressed, more and more vegetation grew, also hindering how easy it was to see and count the crabs. The crabs were not static during counting sessions, meaning they had the potential to be counted multiple times, as well as to move away from the counting area in between counting dates. Lastly, counting could only occur when there was a new or full moon and during low tide.

A population assessment will be conducted by counting fiddler crabs at Spermaceti Cove on Sandy Hook, New Jersey, in order to determine the status of the species, whether or not it is increasing, decreasing, or remaining the same, and, using statistics and past years' data collection, discover any population trends over the years. Ecology, the study of relating the organism to their habitat, will be used in order to determine how the Uca minax species' habitat affects the crabs themselves.  The hypothesis for this study is as follows: Uca minax fiddler crab species located at Spermaceti Cove on Sandy Hook, New Jersey will increase in the future. This longitudinal study incorporates baseline data from the 2016-2017 data collection period and combines it with the data collected this period, 2017-2018, in order to see any trends in the fiddler crab population at Spermaceti Cove on Sandy Hook, New Jersey.