A discussion of best management practices for the South Esk Catchment: mitigation of a diminished aquatic habitat

Abstract

The importance of protecting and conserving sustained aquatic habitats has never been more important as more and more habitats are lost due to a host of imposing threats. Mitigation of impacts from major threats and habitat conservation will ensure future reserves that may be required to further restore diminished habitats and ensure a surviving population of aquatic species.

Globally natural resources have been threatened by human activities, changing ecosystems and climate change. As researchers observe decades of environmental monitoring and expand on extensive amounts of research, it becomes evident that the threats to our environment are extraordinarily complex.

For the purpose of this thesis, focus is placed on one of the most vulnerable habitats today, the aquatic habitat. Many scientists agree that aquatic habitats play a larger role in determining the health and quality of inland waters and ecosystems than their more recognized role in producing a human resource. (Abell, 2009; Graham and Harrod, 2009; Winfield, 2009) Specifically, the global population of Atlantic Salmon (Salmo salar) has remained a desired resource for decades. Only in the last few decades has the severity of population decline become a topic of considerable research as well as the focus of large conservation efforts by private and governmental organizations around the globe.

This thesis discusses the primary threats that aquatic habitats face and how they may respond to a variable environment. Subsequently riparian zone management are examined for its role in ecological functions and the possibility for mitigating pollutant transport for an overall improved habitat. Thereafter, the South Esk catchment area is introduced as a primary site for conservation of aquatic habitats, including the Atlantic salmon. It has been awarded a host of local and regional designations, which ensure its role in the development of improved conservation and management techniques. The catchment has been the site of many years of research regarding aquatic habitats and their decline making it an excellent subject for this thesis.

The study was conducted through the use of desk based research, with a focus on literature specifically applicable to the South Esk catchment. A field study was also conducted of which, the focus of the study was to ascertain potential causes of diminished aquatic habitat and associated characteristics. Observations such as bankside characteristics, riparian vegetation, surrounding land use, pollution sources, and evidence of structural damages were made. Furthermore data was collected with the hope to create riparian buffer zones and inland forested zones. A significant amount of livestock damage was found inland and along the riverbank. There were extreme amounts of bankside erosion and moderate levels of bankside collapse. Additionally, current management efforts such as fencing have remained ineffective in mitigating livestock damage at the river site. Observations in the inland fields noted a significant amount of drainage ditches present and supplying heavy sediment loads to the river. Limitations of the survey method included unexpected weather events, time constraints and inexperience with the survey methods. These limitations should be considered and aimed to be avoided for subsequent surveys.

A discussion of the literature research and field based survey concluded with a primary focus on the involvement of key stakeholder, such as landowners, in the process of developing a management plan. This can prevent issues arising between the private, non-profit and governmental actors involved. Furthermore, the importance of collaborative approaches was discussed with particular focus on issues relating to the removal of land from agriculture in order to be placed into conservation programmes. These relationships can be vital to the success of a management plan. The establishment of buffer zones was established an appropriate mitigation measure for the improvement of the aquatic habitat. Two designs were recommended for use and it was concluded that both grass and woody vegetative buffer types would be successful within the survey site of the South Esk catchment. Furthermore, fencing was shown to be a successful way to increase growth and was suggested as a primary method for mitigation in order to begin natural or planted regeneration of the riparian zone and inland forest areas.

It is the hope that current landowners see a positive result from the work within the survey site, and as a result, become willing to build better relationships with conservation organizations for the betterment of our environment.