Seeing jellyfish from space
16th November 2010
Scientists from PML have been involved in a collaborative study,
to gain further understanding of jellyfish populations in waters
off the west coast of Scotland. The project for the Crown Estate
focused on measuring jellyfish numbers, analysing methods for
detecting blooms of jellyfish and looking at their potential impact
on the fish farming industry.
Since the 1980’s, the European salmon farming
industry has reported an increased impact of jellyfish blooms, when
vast numbers of jellyfish congregate near vulnerable coasts. As
blooms develop around fish farming sites, they can cause a variety
of problems, including reduced availability of oxygen to the fish
by clogging up fish farm cage walls, increased stress to the fish
resulting in reduced feeding, and higher mortality rates caused by
direct killing or injuries to the fish.
Due to the extensive nature of the coastline
and offshore areas to the west of Scotland, monitoring should
ideally be based on remote observation. Two methods which have
shown promise in other locations or similar applications were
trialled. Firstly, an aerial survey was conducted to evaluate
whether the method could be applied to the coastal waters off the
west of Scotland to identify jellyfish blooms. Secondly, remote
monitoring was investigated to see if jellyfish blooms lead to
sufficient water colouration to enable detection by satellite.
Both methods showed promise but there are also
specific limitations; the work undertaken in this project has
demonstrated that no single monitoring method is suitable for all
the jellyfish species of concern but that progress might be made
using a combination of techniques. The ultimate aim is to establish
a robust monitoring and forecasting network for jellyfish blooms,
to provide advance warning of bloom development for the fish
farming industry and other interested stakeholders.