My name is Ellie and I am currently studying Biological Sciences at the University of Essex. Currently, I am on a placement year with Archipelagos, from October 2020 until July 2021.

Here at Archipelagos, I have developed a marine-terrestrial based project investigating the macroinvertebrate communities living within the Posidonia oceanica wracks. Wrack can be defined as an accumulation of detached seagrass, in this case, P. oceanica seagrass assemblage. In particular, I am comparing the species richness, abundance and diversity of macroinvertebrate species on rocky and sandy beaches, with rocky beaches defined as small rock/pebble beaches.

So far, I am already noticing a difference in the richness and abundance of macroinvertebrate species between the two beach classifications. My hypothesis is that there will be an increase in species richness, abundance and diversity of species at rocky beaches as the structural complexity and heterogenous substrate will allow the accumulation of seagrass more readily compared to sandy beaches.

Furthermore, I am looking into expanding this project by investigating the seasonal distribution of Posidonia oceanica on rocky and sandy beaches. According to the literature and from my personal experience, high amounts of seagrass accumulate in winter as this is when the meadows renew their leaves and specific weather conditions assist the transport of material to the shore. However, these weather conditions also lead to high fluctuations in the amount of seagrass wrack found daily within the winter months, which limits the amount of time for the colonisation of species.

I am passionate about forest ecosystems, specifically how trees and the associated fauna interact. I knew I wanted to implement this passion in any way I could at Archipelagos.

Through a detailed and thorough literature review of Posidonia oceanica seagrass I found interest in the complexity and dynamic nature of beach environments and how seagrass influences this habitat. This project can be implemented in a variety of environments and the methodology I have employed could be/has been applied in many forest habitats studies.

I am very much looking forward to analysing the data and seeing the differences/similarities between the species assemblage of rocky and sandy shores, as well as exploring the seasonal differences between wrack in winter and summer months.

As this topic is seldom studied globally, this research is building towards a better understanding of the marine-terrestrial ecotone and emphasising the complex and dynamic habitat interaction, presenting a further ecological understanding of this ecosystem and the services they provide.

Eleanor Hawkins
Biological Sciences student
University of Essex
On-site intern at Archipelagos’ Marine Ecology Team