Fisheries

Pressures and Human Activities mapservice contains datasets on fishing
activity in the Baltic Sea. The service contains three group layers:
  • Fishing effort based on VMS/logbook data 2009-2013 (2015)
  • Fishing insensity based on VMS/logbook data 2009-2013 (2015, note a correction update (v2) that was released in 26 January 2016)
  • Commerical fisheries catches by ICES Squares 2003-2007 (2010)

See below description of fisheries VMS/logbook data processing for the 2009-2013 data. 


PressureS from fishing activity based on VMS/Logbook data in the HELCOM area 2009-2013


BACKGROUND

SOURCE INFORMATION

METHODS

OUTCOMES AND PLANNED USE

CONDITIONS OF USE

CAVEATS


BACKGROUND

HELCOM requires spatially explicit information on fishing activity affecting the Baltic Sea marine ecosystem for policy purposes. In order to obtain this information a joint ICES/HELCOM/OSPAR data call was issued to relevant authorities of Contracting Parties to deliver information on fishing activity based on VMS/Log book data. Upon a request by HELCOM the data was processed to advice data products by ICES Working Group for Spatial Fisheries (WGSFD). Processing of the raw data was done by ICES WGSFD following Conditions for VMS data use, so as to make use of required specific resources, knowledge and guarantee of anonymity for specific vessels.


SOURCE INFORMATION

In 2015 ICES collated Vessel Monitoring System (VMS) and logbook data received; data from Russia were not received. HELCOM requested advice, as fishing abrasion pressure maps as well as fishing effort maps, were provided by ICES.


METHODS

Spatial scope: HELCOM Marine area. All contracting parties except Russia provided data.

Temporal scope: 2009-2013. Calculated values for each year and for each quarter of 2013

Spatial resolution: C-square grid 0.05 x 0.05 degrees

Format: ESRI shapefile (polygon)

The maps and shapefiles of fishing intensity and effort were calculated for bottom contact gear and mid-water trawl and longline for every year in the period from 2009 to 2013 and for each quarter of 2013. The following maps were produced:

i) intensity of fishing by each fishing activity for each year in the period from 2009 to 2013;

ii) total intensity for each year in the period from 2009 to 2013;

iii) total intensity and by each fishing activity by quarter in 2013


HELCOM secretariat did the following further processing to the data:

- Conversion to ETRS89LAEA coordinate system

- Added attribute "Reported" to display unreported area (Russian EEZ).


Dataset attribute information:

c-square: Unique reference of the c-square polygon

mid_lat: latitude coordinate of the centroid of c-square inWGS84 decimal degrees

mid_lon: longitude coordinate of the centroid of c-square inWGS84 decimal degrees

Year: Year of fishing activity

quarter: Quarter of the year, if applicable

geargroup: Fishing gear group (Effort maps)

SubsurfSAR: Subsurface swept area ratio (Intensity maps)

SurfSAR: Surface swept area ratio (Intensity maps)

Fishing_ho: Total fishing effort in hours within c-square (Effort maps)

Reported: Yes=Reported data. No= No reported data (area that does not contain effort/intensity value due to lack of reported data).

 

Following definitions given in ICES advice to OSPAR, understanding of "fishing intensity" is clarified in the fishing abrasion pressure maps produced for the advice to OSPAR. Abrasion pressure is not appropriate for midwater trawls and longlines; therefore, maps for all gears have been produced using fishing effort as the number of hours fished, extracted from the submitted VMS data.

Using methods described by ICES WGSFD, fishing abrasion pressure maps were produced for mobile bottom-contacting gears. In line with the methodology, separate maps were produced for surface and subsurface abrasion. The resulting maps showing fishing abrasion and fishing effort have also been provided as ESRI shapefile data to HELCOM and are available via HELCOM Map and Data service. When using these data caveats listed in the section "Conditions of Use" should be considered.


Outcomes and planned use

The outcome data products display fishing intensity and effort in the Baltic Sea. Largest swept area ratios and fishing effort for subsurface abrasion of mobile bottom contacting gear were found in the Southern Baltic and Kattegat. Highest fishing effort for midwater trawls was located in Eastern Gotland Basin and Gulf of Riga. Fishing effort using longline gear was mainly focused in Bornholm Basin. The fishing effort was also calculated per each 174 HELCOM Marine Protected Area (MPA).

 

Analysis was also carried out on proportion of fisheries represented by the data. The proportion of the total landings (by weight) that was recorded by logbooks and are represented by VMS data increased in 2012 compared to earlier years, in 2012 VMS became mandatory for >12 m vessels. In 2013 VMS data captured 81.6% of total fisheries for all mobile bottom-contacting gear, for midwater trawls 99.6% of the landings are covered by VMS, and for the longlines only 23% of the landings are covered by VMS.

Read full advice text here.


Conditions of use

The data products derived from the HELCOM requested advice from ICES are downloadable from HELCOM Map and Data service and can be used freely given that the source is cited. Requested advice can be used as appropriate by HELCOM when embarking on further marine policy related issues.

The correct data product citation is following:

ICES. 2015. Fishing abrasion pressure maps for mobile bottom-contacting gears in HELCOM area. HELCOM requested advice from ICES.


CAVEATS

When using the data for analysis/assessments the following caveats need to be taken into consideration:

  • Data from Russia were not received
  • The methods for identifying fishing activity from the VMS data varied between countries; therefore there may be some country-specific biases that ICES cannot evaluate. Additionally, activities other than active towing of gear may have been incorrectly identified as fishing activity. This would have the effect of overestimating the apparent fishing intensity in ports and in areas used for passage.
     
  • The data for 2012 and 2013 is not directly comparable to the data of previous years in the data call (2009–2011) due to the gradual increase in VMS-enabled vessels in the range of 12–15 m. This is likely to be most relevant when examining trends in effort for inshore areas.
     
  • Many countries have substantial fleets of smaller vessels that are not equipped with VMS (< 15 m prior to 2012, < 12 m thereafter); logbook data is at the spatial resolution of ICES rectangles, but where possible, they have been overlaid with the VMS data for the purpose of analysis.
     
  • The fishing abrasion pressure methodology is based on very broad assumptions in terms of the area affected by abrasion. A single speed and gear width was applied across each gear category in most cases, which can lead to both underestimates and overestimates in actual surface and subsurface abrasion.



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