The number of fish in the world’s oceans has halved since 1970 . This is due to the inflation of the world’s population, and a greater reliance on fish as a protein source for many communities [2, 3].
Along with an expansion in population, advancements in technology have increased the pressure on fish stocks through the use of increasingly efficient fishing practices . Together, these factors make over-exploitation an ever-pressing concern.
With risks of jeopardising the future supply of food, and reducing the variety of life on Earth, monitoring marine ecosystems is an important action towards the sustainable use of ocean resources.
Importance of Marine Ecosystems
A report from the year 2000 estimated that one billion people worldwide rely on fish as their primary source of animal protein . Two decades later, and that figure has tripled to three billion – around 40% of the world’s population . Not only are fish feeding communities, they are also the basis of the livelihoods of millions.
“A consistent source of fish is essential for the nutritional and financial health of a large segment of the world's population.” .
The importance of fish as a protein source cannot be understated. Therefore, as this key resource can be depleted, it makes sense to monitor the ecosystems that fish inhabit. Monitoring can provide early warning indicators of when fish stocks are declining, and can help to ensure continued provision of fish as a source of food and income.
In addition to the harvest of fish for seafood, marine ecosystems provide key services and benefits . Services such as:
Not all of these services are lost as a direct result of over-exploitation of fish stocks. However, the interconnected nature of the marine seascape means overfishing in one area can indirectly affect other parts of the seascape .
It can be seen that knock-on effects of ocean resource use quickly become challenging to monitor. However, where there is challenge, there is opportunity for growth. Thus, it can be expected that as our knowledge of ecosystem services increases, with it, our progression to sustainable ocean use will strengthen.
Ways to Monitor
The need to monitor marine ecosystems for environmental and fisheries maintenance has been recognised since the 1880s . In these early days of marine environmental monitoring, information came from commercial fisheries (e.g., fishing effort, quantity/value of landings) and hydrographical data (e.g., temp, salinity) .
With the ever-growing threat from climate change, the need to monitor marine environments has never been greater. Fortunately, recently developed technologies such as DNA microarray and Real Time qPCR, as well as remote sensing and acoustic methods, enable the effects of climate change to be closely monitored .
General methods for monitoring the marine environment include:
As technology advances, more innovative ways of monitoring marine ecosystems arise. However, without a holistic framework to identify the higher risk ecosystems, data from environmental monitoring loses an element of direction.
The global standard for assessing ecosystem risk is the IUCN Red List of Ecosystems, which was officially recognised in 2014 . This risk assessment tool aims to assess all of the world’s ecosystems by 2025. An ambitious goal, nonetheless, this has potential to pull together monitoring data from all corners of the ocean.
Through doing this, efforts can be more accurately directed to the ecosystems that are threatened with unsustainable resource use.
In an age of technological advancements and population growth, humans have the potential to decimate the natural environment. It is our responsibility to direct advancements towards a sustainable future.
Written by Miles Smith, a current master’s student with University of Exeter and NLAI associate; studying Marine Vertebrate Ecology and Conservation. Miles is particularly interested in behavioural ecology and how this field of study can be applied conservation issues, and how solutions to these issues can work for biodiversity and human communities alike.