Stress
In the first topic in this module, we examined key features of the marine environment and differences between marine and terrestrial systems. In this second topic, we look in more detail at some of the stresses operating in marine environments and how organisms respond to them. We focus on intertidal environments, particularly rocky shores, because these are places where stresses are obvious and easily examined.
1. Stresses in marine environments
An overview of this topic is given in the following Stress in Marine Systems video lecture presented by Dr Keith McGuinness:
https://www.youtube.com/watch?v=slI9BjNybtA&feature=youtu.be
Intertidal rocky shores are a useful environment in which to study stress in marine organisms:
- the habitat and the organisms are readily accessible;
- due to the tides, there are pronounced changes in stress over relatively short spatial and temporal scales;
- and the organisms are mostly small and slow moving, so they are easily observed and manipulated.
As a consequence, the ecology and biology of the communities of organisms inhabiting rocky shores may be the most intensively studied of all environments, terrestrial or aquatic.
In this topic, we will examine some of the stresses that organisms living in intertidal environments, particularly on rocky shores, face and how they have evolved to cope with these.
Read an introduction to intertidal rocky shore habitats: TÖPKE, Katrien (2021): Rocky shore habitat. Available from http://www.coastalwiki.org/wiki/Rocky_shore_habitat
Note: This article provides a good introduction to the physical features of intertidal rocky shore environments (and note that much also applies to intertidal coral reefs) and to the different stresses that the organisms face. The information on zonation, however, is rather less useful, being overly simplistic. For instance, if you live near a shore, stand at the top and try to identify decide where the boundaries between the high tide and middle tide zones, and the middle tide and low tide zones, lie. Further, the other readings will illustrate the complexity of biotic and abiotic processes occurring in these environments.
The second part of this topic considers organism responses to stress.
References
A note about Wikipedia: some love it, some hate it; a college in the US has even banned its use. But "According to Leupp [one of the staff at the college], no source is truly credible. To him, choosing which information to believe is what learning is all about." Leupp says that the ban is "irrational". I agree but don't I think "choosing which information to believe is what learning is all about" but learning to evaluate the quality of information is important. You will see in these pages that I refer to Wikipedia, and to other similar projects (e.g. coastalwiki) but I also add notes when I think some of the information is incorrect or inaccurate. Wikipedia, and similar efforts, have one advantage over many of the research journals: linking to them is free and easy. (There are increasing numbers of open access research journals becoming available and, in the face of competition, existing journals are increasing their accessibility.) There are disadvantages – the information may not be checked for accuracy and completeness, a page may change in major ways over time – so in choosing the sources to use here I am trying to balance ease of access with accurate information.
TÖPKE, Katrien (2021): Rocky shore habitat. Available from http://www.coastalwiki.org/wiki/Rocky_shore_habitat
Extra reading:
Lathlean, J. A., & Minchinton, T. E. (2012). Manipulating thermal stress on rocky shores to predict patterns of recruitment of marine invertebrates under a changing climate. Marine Ecology Progress Series, 467, 121-136. https://www.int-res.com/articles/meps2012/467/m467p121.pdf