The fish and fisheries module

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Large Marine Ecosystems: Assessment and Management

31 classificação

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University of Cape Town

Large Marine Ecosystems: Assessment and Management

31 classificação

Focusing on the Large Marine Ecosystems (LMEs) of the world, this course will introduce the concept and practice of ecosystem-based management. LMEs occupy areas of coastal ocean at least 200 000 km² or greater in size. These coastal waters produce 12.6 trillion USD in ecosystem goods and services annually and are vitally important for billions of people around the globe. Because LMEs are bounded by ocean features and are globally linked, management of human activities needs to occur in an integrated fashion across political boundaries and economic sectors (e.g. fishing, shipping, energy, tourism, and mining.) This represents a new type of management approached - shifting from single sector-based to multi-sector assessment and management within the spatial domain of the world's 66 Large Marine Ecosystems. There is global high-level support for this new approach and in this course, we will introduce the concepts and tools for assessing and managing LMEs. Together, leaders and experts in a global movement to recover and sustain the goods and services of LMEs will introduce you to the mechanisms used for assessment (Transboundary Diagnostic Analysis), planning and implementation (Strategic Action Programme). Based on recent activities in implementation and practice of the LME approach in 22 projects around the globe, we will showcase examples of effective management at this scale, and highlight the challenges and issues. By the end of the online course, we hope you will be able to actively use this knowledge to advance sustainable development of the world’s oceans. The course was created with the support and input of: the Global Environment Facility (GEF), the United Nations Development Program (UNDP), the National Oceanic and Atmospheric Administration (NOAA), UNESCO-IOC and IW:LEARN.

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The Three Natural Science Modules

In this week, we deal with the three natural science modules within the five module approach.

The fish and fisheries module5:21

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Coleen Moloney
Associate Professor
Marine Research Institute

Fish and Fisheries is

one of the five modules in

the large marine ecosystem approach to ecosystem-based management.

It merits special consideration because of

the importance of fisheries to countries for food security,

for their economic value,

and also for their links to cultural heritage.

But it also is important because fishing operations impact marine ecosystems.

Information in the Fish and Fisheries module is used to assess the abundance,

and the health of important marine species targeted by

capture fisheries and mariculture and also the health of the ecosystem.

These assessments can draw on traditional fisheries data and stock assessments,

but when interpreting changes in fish populations and fisheries,

the direct impacts of fishing can be difficult to

disentangle from other influences caused by climate change,

pollution, ocean acidification, and a range of other factors.

For adaptive ecosystem-based management,

these effects of multiple factors need to be considered.

Information is also required to consider the impacts of

fishing on the whole ecosystem through its effects on habitats,

biodiversity, and the marine food web

all of which feedback to the state of the fish stocks.

Mean annual global fish catches can be analysed and presented in various ways,

but these generally show that the catches peaked in the 1990s.

The available reported data indicate a leveling off of catches from the 1990s onwards,

but when these data are supplemented by

unreported catches the reconstructed data set indicates a decreasing trend.

Today, many large marine ecosystems have fish stocks that are

classified as being collapsed or over-exploited and

over-fishing is a common ecosystem issue identified in

TDA reports from almost all large marine ecosystems.

In addition to impacts on the fish that are caught,

fishing also impacts marine ecosystems in a number of ways.

Ecological impacts result when a fished population is

reduced causing cascading effects up and down marine food webs.

There can be impacts on the prey, the predators,

and the competitors of the fished population as well as

on other species caught as bycatch in the fishing operations.

Ultimately, unregulated and poorly regulated

fishing activities impact human welfare in terms of food security,

employment, and economic benefits.

The indicators for fishing generally are constructed by combining

information in order to summarize complex processes often as a single number,

which then needs to be easy to understand and to communicate.

Fisheries indicators are used in traditional fisheries management where information

is collected and analysed for single fish species or sometimes for species groups.

Traditional fisheries indicators can be used

to guide single species fisheries management,

but under an ecosystem approach,

these need to be supplemented by ecosystem indicators to allow

assessments of the state of the whole fish community or of the whole ecosystem.

A number of research groups have been working on developing and applying

indicators to support an ecosystem approach to fisheries management.

Another useful resource for indicators is provided

by the Sea Around Us Project in which scientists from

the University of British Columbia have developed and made

available indicators for assessing fisheries in large marine ecosystems.

One of the ecological indicators that they use to show the impact of fishing is

the Marine Trophic Index which tracks

how the mean trophic level of the catches changes over time,

assuming, that a decrease in this indicator typically

indicates that large predatory fish have been overfished in the ecosystem.

So, in summary, the Fish and Fisheries module is important for

ecosystem-based assessment and management of the world's large marine ecosystems.

The module is closely linked to the productivity module and the pollution and

ecosystem health module because these two

affect the carrying capacity of the large marine ecosystem.

It also has strong links to the two modules on the human dimensions,

because good governance is so important for

effective fisheries management and fisheries are so

important for coastal countries around the globe.

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