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In Other Words

May 19
Fisheries genetics

​Naiara Rodríguez-Ezpeleta of the Working Group on Application of Genetics in Fisheries and Mariculture (WGAGFM) and co-organizer of the EuroMarine Foresight Workshop on the Application on Population Genomics to Fisheries Management.”​

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'The genetic information stored in each of the cells of the individuals of each species can provide crucial information for understanding processes that cannot otherwise be studied or provide more cost-effective measurements than traditional methods. 

Species identification can be achieved using barcoding: the amplification of a short variable DNA fragment that, compared against a reference database, is used for taxonomic assignment. This technique is particularly relevant for morphologically similar species (e.g. black and white anglerfish), early developmental stages (eggs and larvae), semi-digested specimens (e.g. stomach contents) or animal pieces (e.g. shark fins).

Stock delineation can be achieved using population genetics, which relies on the analysis of genetic markers that are variable within a single species (microsatellites and SNPs are the most widely used ones). If a large number of these markers are conserved within a group of individuals, it may indicate reproductive isolation​, either due to distance (isolation by distance) or reproductive behavior (homing) for example.

Origin assignment can be achieved by typing on the individual to be assigned a subset of informative markers from the ones identified during the stock delineating process. This is particularly relevant for identifying the origin of a landed catch or to assign individuals to a stock in the case of mixed-stock fisheries (e.g. salmon caught at sea can be assigned back to its river of origin).

Adaptive genetic changes can be identified by studying those markers that present the same variants within individuals that inhabit similar conditions and that are not the result of isolation by distance. (e.g. same genetic markers are responsible for the adaptation to warm temperatures in cod inhabiting the east and west Atlantic).

There are many other fishery assessment questions to which genetics can provide relevant information. Recently, two methods that promise to revolutionize the field are 1) the close-kin mark recapture method, which potentially allows estimating fisheries independent abundances from genetic data and 2) the analysis environmental DNA (eDNA), which is DNA released into the environment in the form of skin, blood, mucus, for example, which can provide information about the species inhabiting a given environment without needing to see or sample them.'


April 07
Marine Spatial Planning

​Jacqueline Tweddle, member of the Working Group for Marine Planning and Coastal Zone Management​ (WGMPCZM)​, along with group chairs​ Andrea Morf and Matt Gubbins

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'Marine Spatial Planning is a process for deciding how best to use our marine space. For centuries, the sea has been free and open to everyone, but now there are more demands for different and exclusive uses as well as requirements to ensure we maintain a healthy marine environment.  Marine spatial planning (sometimes referred to as marine or maritime planning or, when close to land, coastal zone management)‎ is a process through which recommendations are made on the use of marine space, allocating space with the goal to balance environmental, societal and economic needs. This negotiation and decision making process is to be open and transparent, engaging with “stakeholders” affected by those decisions. The resulting plans usually consist of several parts: a section showing how the sea is used today and what issues need to be addressed, a general vision on the future use of the sea, and what uses to prioritise where.

‎Often there are gaps in our knowledge about what the optimum use of our marine spaces should be to achieve societal objectives and ensure sustainable uses of our seas. We are in an intensive phase of developing our knowledge and methods to understand the consequences of planning decisions. The ICES Working Group on Marine Planning and Coastal Zone Management is working on the development of knowledge and methods for this purpose - in close collaboration between science, society and policy makers across different disciplines and seas, from the Baltic over the Arctic and the Atlantic to the Mediterranean and beyond.'

March 14
Benthos

​Silvana Birchenough Chair of the the ​​​Benthos Ecology Working Group (BEWG)​ and the Steering Group on Ecosystem Processes and Dynamics (SSGEDP)​​​​

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'The concept of 'benthos is used to refer to organisms or a community of organisms that live on, in, or near the seabed, also known as the benthic zone. Depending on their size, they can be classified into macrobenthos (greater than 1 mm), meiobenthos (less than 1 mm but greater than 0.1 mm) or microbenthos (less than 0.1 mm). There are also different types that can be classified into zoobenthos (all benthic organisms) and phytobenthos (including benthic diatoms and macroalgae or seaweed). 

Benthic organisms are important, as they play a key role in marine ecosystems, helping to deliver many ecosystem goods and services, ranging from biodiversity, remineralization of nutrients, long-term carbon storage and provision of food for high trophic levels. These are just some main activities fueled by the benthic system. There are many more.'

March 06
Fishery-dependent and fishery-independent information

​​​​Mike Armstrong, co-chair of the ​​Benchmark Workshop for Sea Bass (WKBASS)

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'ICES provides advice each year on the state of fish stocks in European waters, as well as options for future fishing opportunities in line with the principles of sustainable fishing. Where does ICES obtain the evidence to support its advice? Fish, invertebrates and their predators are largely out of sight below the water surface and it is clearly impossible to count and measure all the individuals in the population. We must sample the population to find evidence for changes that are taking place. The main sources of data are from the fisheries themselves and from sampling programmes independent of the fisheries.

Fishery-dependent data include mandatory data on catches and fishing activities supplied by fishing skippers, as well as representative sampling of fishing trips to estimate discarded and recreational catches not reported through logbooks. In some fisheries, the trends in quantities caught per unit of fishing effort (e.g. per day) can provide evidence on trends in stock abundance. Sampling on shore and at sea provides information on the size and (where possible) age of individuals in the catches. These data can be used to estimate the annual fishing mortality rate, an indicator of the proportion of the stock removed by fishing during the year which can be compared with values considered sustainable.

Fishery-independent data are collected, for example, from research vessels using trawls, acoustic systems, underwater cameras and planktonic egg samplers to collect data on abundance and composition at stations or transects positioned randomly or systematically across the geographic range of the stock. Many such surveys also provide other data on the ecosystem. Fishery-independent data can be used on their own to provide advice on stock trends, but ICES often includes them with fishery-dependent data in assessments to provide the most accurate estimates of stock trends, stock status and future fishing opportunities.'

September 23
Non-indigenous species and ballast water in Canadian Arctic

​Masters student Pascal Tremblay of the Université du Québec à Rimouski, Canada, exlplains his poster 'Assessment of nonindigenous species introduction risk through ballast water discharge of a domestic ship in the Canadian Arctic'.

 Pascal's co-authors are André Rochon, Gesche Winkler, Kimberly Howland, Nathalie Simard, and Sarah Bailey.

September 23
Aged and children first!

Masters student Stefanie Haase tells us about her Annual Science Conference poster 'Aged and Children first!' about challenges in the development of a new selectivity concept for trawl fisheries.

Stefanie's co-authors are Juan Santos, Annemarie Schütz, Bernd Mieske, and Daniel Stepputtis.

See high quality poster here

September 23
What's on cod's menu?

Nataliia ​Kulatska from the Swedish University of Agricultural Sciences explains her Annual Science Conference poster 'what's on cod's menu?' about the fisheries effects on the interactions between species as well as on their population dynamics and size structure.

Nataliia'a co-authors are: Valerio Bartolino, Håkan Wennhage, Bjarki Elvarsson, and Gunnar Stefansson.

See the poster in high quality here  

June 24
Upwelling

​Kai Myrberg, ​​​Vice-President of ICES Bureau​.

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'Upwelling is a procedure which happens in the sea, where cold and nutrient-rich water comes up from the layers below the surface. In such a case there is enrichment of the biological activity and processes. There are a lot of nutrients which means there are also a lot of fishes to eat the plankton that is available. It couples physical and biological processes in fisheries, so in this respect it's important.'​

June 23
Trophic interactions

Bill Karp, Vice-President of ICES Bureau.​​

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​'Trophic interactions are all about who eats whom. It's based on this idea of a trophic pyramid, where there are different levels – called trophic levels. The lowest level contains plants, phytoplankton. Then the next level, which is the first level of consumers, contains small animals that eat plants. Then as you get higher and higher you get bigger animals, fish, and marine mammals that are less dependent on plants and more dependent on bigger and bigger animals.

It's important because these interactions amongst animals and plants that are eaten or eat characterize the ecosystem, and we have to try really hard to understand quantitatively what the energy flow is across these different levels and what the mortality is associated with consumption, which then is part of natural mortality, which is an input into stock assessment models, or in a more complex way because of all these interactions into ecosystem models.'


June 22
Pelagic

President of ICES Bureau​​ Cornelius Hammer.

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'Normally pelagic is perceived as the open water. When you leave the coast, you cross water that is about 100-200 metres deep – the continental shelf – and then you are out in the open sea. What's underneath you is pelagic. The seemingly unstructured open water without boundaries. However, it is structured. We normally can't perceived this though. For the plankton that floats through the pelagic area and the fish that swim through it or drift with the currents, it is very structured. There are different water bodies and also movement of these horizontally and vertically.

There are areas where deep water rises, brining nutrients to the surface. With these nutrients there is diverse and productive life, which attracts predators. So in the middle of a seemingly uniform environment you find hotspots of life; other areas are pretty empty. Often you have huge visibility with little light. We call it the 'desert of the ocean'. It seems to be clear water, but from the perspective of an animal or plant in the environment it is a desert. Most of the pelagic is this clear water, but not all of it. There are huge horizontal and vertical movements; for instance in the pelagic North Atlantic, this is very productive, the water isn't that clear. The desert storms from the Sahara bring dust clouds which precipitate and fertilize the area with iron. This helps phytoplankton life and makes the water green and non-transparent. That again is the basis of zooplankton growth and then fish and mammals.

Between the Faroes and Iceland there is a huge barrier and the water from the north floats over at 200 metres deep over this barrier and falls down to three thousands metres. So there's a waterfall within this vast pelagic area. There's a lot of physical and biological activity going on in the pelagic environment, it's not just a uniform environment.'​

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In Other Words is a blog devoted to clarifying some of the important terms and phrases that are crucial to the work we carry out as well as the wider world of marine science.

Each week we'll feature a scientist or expert from one of our working groups, who will explain a term relevant to their efforts In Other Words.

Stay tuned!