Assessing ideal shore height for Cerastoderma edule, common European cockle: Using cockle length and diversity at individual shore heights

INTRODUCTION 

Cerastoderma edule, the common European cockle is a bivalve mollusc widely distributed around Northern Europe’s coastline, commonly found in estuaries with sheltered shores (Coscia et al, 2012). Living in intertidal sedimentary shores up to 5cm in muddy sand, where burrowing in sand reduces predation risk while being able to feed on plankton brought in by the tide is an ideal habitat for these species (Lezcano et al, 2016). Common cockles are especially affected by predation and tides as well as salinity, where their optimal salinity range is between 20-25, an increase or decrease would lead to severe mortality rates. Being filter feeders’ cockles rely on the tide to bring in phytoplankton to feed, however in return they are preyed upon by other marine organisms such as Oystercatchers, Haematopus ostralegus and the common shore crab, Carcinus maenas (Sanchez-Salazar et al, 1987). Cockles are important for biodiversity, playing a crucial role in ecosystems such as water filtration and biogeochemical cycling, as well as support ecosystems and creating new habitats (Carss et al, 2020).

Climate change and its impact on sea turtle sex ratios.

Introduction

Earth climate has varied since the existence of the planet, varying between ice ages and extremely warm periods. Climate change has shaped the earth, its geographical and physical features, due to continuous underground tectonic plate movements and erupting volcanoes, changing the composition of the atmosphere (Goudie, 2009). However, since the beginning of the modern climate era, changes in global temperature are essentially due to human activities, through the overuse of fossil fuels. Climate change is the anthropogenic induced change that has caused detrimental effects to the earth global climate due to an increase of greenhouse gases from human emissions (McMichael, 2006). Climate change has shown to affect many types of environments such as ice melting, variability in the seasons, rising sea levels, temperature variability including heat waves and many more accelerated effects. Climate change has shown to have severe implications on marine ecosystems, changes in ocean chemicals, circulation and temperature have significant consequences linked to population dynamics and the probability of a stable population growth (Harley, 2006). The survival rates of many marine organisms are affected by global warming, especially the increasing temperature of the atmosphere and oceans, leading to population distribution shifts.

Marine sea turtles, distributed in the tropical and subtropical seas are heavily reliant and influenced environmental global temperatures, showing high sensitivity to thermal conditions (Mazaris, 2008). This essay focuses on climate change and its effects on marine sea turtles sex ratios, their adaptations and mitigation strategies.

Comparing Haematology and Immunity

 in A. Rubens and M. Edulis

........ A. Rubens has a higher mean concentration coelomocytes per µl than M. Edulis, this may be due to the Starfish having a more complex immune system that requires these cells, whereas the mussel is a more basic structure. Number of haemocytes is dependent on environmental factors (diseases or pathogens in the water), therefore may be specific to the species, or coincidental. Figure 3 shows both species have a higher concentration of hyalinocytes, although mussels have a larger difference between granulocytes and hyalinocytes (12.96%) compared to the starfish with a much smaller percentage difference (6.16%). Hyalinocytes are involved in broad innate defence immune system functions including phagocytosis and healing whereas granulocytes are involved in innate responses against exogenous pathogens, therefore leaning more towards the adaptive immune system. Hyalinocytes are more present due to their ability to contribute to various functions, therefore more useful when the species need to repair tissues (e.g., the needle hole) or digests foreign particles.