Sand Crabs

Limpets (Patella vulgate) live in algae rich environments on rocky shores. . It has been proposed that in more sheltered areas, limpet shells will grow to be flatter with a larger diameter, while in more exposed areas of coastline, they will grow a taller and narrower shell shape. To find out whether or not the shores of Aberdeen reflected this, samples were taken from two sites (Site A and Site B) along the Aberdeen coastline that varied in their exposure to wave action. The sites were chosen to provide two sample sites with a notable difference in their environment. In the more sheltered site A, limpets were not exposed to harsh waves, while at site B, there was significantly more wave action. Quadrats were used at both sites to provide an area of sampling for the limpets and they were placed around 5 meters from the waterline. The overall results from the study showed that there is a very strong relationship between diameter and height in Limpet shells and that there was an incredibly slight difference in the relationship between the two sites.

The profile of Pallarenda beach as shown in figure 1 is very typical of a North Queensland, medium energy beach. The lack of organisms present higher up the beach was due to the harsh conditions at low tide. Ghost Crabs, Ocypode quadrata, can survive these areas as a result of their adaptations (The Otter Island Project). The ghost crab burrows during the day and feeds at night to avoid the heat of the day (The Otter Island Project). These crabs can actively take up moisture from damp sand to wet their gills (The Otter Island Project).

Horseshoe crabs are an important part of the wetland ecosystem, however they are going extinct. Due to harvesting, pollution, and other animals consuming their offspring their numbers are dwindling. They play an important part in the ecosystem and need to be protected so they do not become extinct. The Delaware bay has decided to protect them for their future uses in medicine and to keep them as an important role in the ecosystem.

Three years ago, the author took a trip to Delaware. As his family was walking on the beach they came across some horseshoe crabs mating. He wondered how they have changed. The type of horseshoe crab he saw along the beach was called “limulus polyphemus”. Limulus Polyphemus is not found in the fossil records. The fossil record for horseshoe crabs is deeper than 20 million years, and the

Knowing how many horseshoe crabs there are helps fisheries managers develop effective policy for managing populations. You can help by volunteering to count the crabs in May and June.

Lobsters are benthic organisms because they on the ocean bottom (Townsend, 2012). These animals are on the bottom of the seabed and do not swim as much as organisms that never touch the seabed (Townsend, 2012). In this case, epifaunal is a word to characterize that lobsters live on the seabed (Townsend, 2012). Lobsters do not burry themselves into the seabed, but instead hind under rocks for protection from prey (Townsend, 2012). In addition, the mobility of lobsters was designed to catch prey and the mobility of a lobster is used for a survival technique that is heavily influenced based on feeding styles (Townsend, 2012). Furthermore, feeding styles increase growth in a lobster therefore molting and temperature of ocean are also important to study (Townsend, 2012). Studies are trying to find correlations that climate change can be linked to molting patterns, or with more carbon dioxide in the water lobsters carbon shells could be impacted (Townsend, 2012). Surprisingly, after over twenty years of studying many lobsters researcher Dr. Jelle Atema has come up with a detailed explanation for lobster mating behaviour where female lobster does not have a shell (University of Maine, 2016). On the other hand, Dr. Robert Steneck debates technology is best used to understand the lifestyle of a lobster (Gulf of Maine Research

Horseshoe crabs have been on the earth since 30 million years ago which is before the dinosaurs lived. The Delaware Bay has the biggest population of horseshoe crabs in the world. In Delaware, the horseshoe crab population has decreased rapidly which is a problem for the environment. Many shorebirds that migrate, rely on horseshoe crab eggs for food. Also, the biomedical industry depends on horseshoe crabs for the substance, Limulus Amoebocyte Lysate(LAL) that is found in the blood of horseshoe crabs. Finally, fisheries use horseshoe crabs as bait for eels and whelk. Delaware researches and protects horseshoe crabs to benefit the environment and humans.

Additionally, the Callinectes sapidus, otherwise known as the blue crab is another native species of the Chesapeake bay. It's decline has been quite evident to the bay and has many effects. With the oysters in the bay, the crab population had been cut by half, from 1980-1990, to 300 million. In 2008, it was reported that the population was declining by 70%. It was quite evident to the researchers that the blue crab population was decreasing due to poor water

The blue crab Callinectes sapidus is a wide-ranging, ecologically and economically important species along the Atlantic and Gulf of Mexico (GMx) coasts of North America. Consequently, its basic biology, life history, population genetics, and demography have been the subjects of numerous studies. For my dissertation research, I propose to focus on two critical areas concerning the ecology and evolution of blue crabs that have broader implications for our understanding of marine organisms with biphasic life cycles. For the first chapter I will investigate the unusual finding of extreme temporal and spatial variation in the genetic composition of settling blue crab larvae along the Texas coast. Since it was reported in 1993, this finding been

The aim of the present study was to test the hypothesis that the invasive red king crab, Paralithodes camtschaticus, may hamper capelin recruitment through egg consumption, by carrying out fieldwork studies (2005, 2006), laboratory experiments (2011), and applying models of consumption. To explore the response of the predator to prey density, crab abundance and capelin egg density were estimated in stratified study areas. An exponential decay model was used to estimate stomach evacuation rates of capelin eggs in red king crab stomachs, and the average evacuation time estimated was 5.38 h at 2.9°C. The average evacuation time was applied to a consumption model where uncertainty in input values was assessed by Monte Carlo simulation. Estimated

The coral reef surveyors were instructed to find the best sites that they believed had the most living coral and were thought to be least affected by human activities. This would allow Hodgson to determine if human activities were having an appreciable effect on the supposed pristine coral reefs, which were distant from urban centers. The invertebrate survey was undertaken at two depth intervals of 3m and 10m. Four 0.5 m wide by 20 m long belts were placed on the coral reef. Over a period of 3-5 minutes the observers counted the number of invertebrates found on the belts. The coral survey was performed, by placing four 20 m long belts on the coral substrate. At 0.5 m intervals the substrate on which the belts were lying was examined and recorded.

The intertidal rocky shore of Caloundra Beach is inhabited by diverse range of biodiversity of animals and plants, many of which have developed high levels of adaptations throughout their existence. The very boundary of marine and terrestrial ecosystem, this environment is subjected to extremes of the physical environment such as temperature, desiccation, wave turbulence as well the ecological interactions that commonly occur in biotic communities (e.g. competition, predation). However Rocky intertidal shores are easily accessible by humans and provide an enjoyable opportunity for passive recreation and for science and environmental education as well.

Mussel Mytilus Californianus are a part of a benthic invertebrate populations along wave-exposed intertidal coast lines of western United States. Mussels are in the family of the most endangered species in America, with over 70% of the taxa being considered threatened (Williams, 2011). This can be partially attributed to the fact that they are heavily impacted by both abiotic and biotic factors on regional and greater geographic scales. Biotic and abiotic factors manipulate species geographical boundaries such as tide height and latitudinal distribution (Sorte & Hofman, 2005).

Red king crabs were collected for stomach analysis and abundance estimates by using a specially designed beam trawl, previously used in surveys for stock assessment by the Institute of Marine Research (IMR). The crab trawl is 6 m wide, 1 m high, and is equipped with a 135 mm mesh size polyethylene net (Sundet & Berenboim 2008). The hauling speed was approximately 1.65 kn. It was not possible to use a fixed standardized trawling distance because of the changing and rocky bottom topography. Four hauls were also performed with a shrimp bottom trawl in 2005, to catch fish for stomach analysis for another study not included in this paper. However, as red king crabs were caught during four of these hauls (Table 3), stomach analysis of these crabs

My investigation was to analyse the ecological pattern of zonation within the Pauatahanui Inlet estuary at Motukaraka Point. Our focus was to compare the distribution of invertebrate species from the low tide point to the high tide points of the estuary. This estuary is formed by fresh water from streams meeting saltwater from the Tasman Sea. We found the pattern of zonation by randomly placing three 0.3m x 03.m quadrats at 5 metre intervals along an interrupted belt transect line that was placed at a right-angle to the estuary mouth (Low Tide Point). We recorded the number of invertebrate organisms on the surface of the mud within the quadrat and then dug down 5cm below the surface to observe the organisms located there. The main abiotic factor that affects these organisms is aerial exposure (tidal movement), we also measured the abiotic factors that affect these organisms, and these included salinity percentage, pH levels, temperatures of the air & substrate and the light levels. The invertebrates we will be investigating are the Tunnelling Mud Crab (Helice Crassa) and the Cockle (Austrovenus Stuchburyi). Due to the mud crabs natural instinct to hide in their burrows when approached, one mud crab burrow was counted as a single mud crab. Also this particular estuary had consistent cover of single cockle shells from the deceased invertebrates, to ensure we