Commercial Fishing

Subtopic

Communities at Sea

Communities at Sea data show linkages between fishing communities and the fishing places that are most important to them. The maps are developed by linking Federal Vessel Trip Report (VTR) data (trip dates, gear type, number of crew on board, trip locations) with vessel permit data (vessel length, ports associated with each vessel).

The relative importance of fishing areas is measured in “fisherdays” based on the number of days that vessels spent fishing in any given area and the number of crew members that were aboard. Fisherdays do not reflect other variables such as number of pounds landed, value, or other common measures of fishing activity or effort; however, the map legends use the term “fishing effort” for simplicity. The maps can be interpreted as showing community presence in ocean areas. Two types of Communities at Sea maps are available:

• Regional maps show where fishing occurs with different gear types—bottom trawl, dredge, gillnet, longline, or pots and traps—and the relative importance of different places. The dataset includes vessels from all ports. For example, the places frequented by fishing vessels using bottom trawls or dredges can be visualized separately. Regional maps are shown by default or can be viewed by selecting All Ports in the Location dropdown menu.
• Port-specific maps indicate the most important places for fishing vessels associated with a selected port. The outline on the map represents where fishing vessels from that port conduct 90 percent of their fishing activity.For example, the places frequented by fishermen from New Bedford, Massachusetts, who fish using gillnets can be mapped separately from places frequented by gillnet fishermen from Portland, Maine. In addition, the places where New Bedford vessels fish with bottom trawls can be mapped separately from places that they fish with dredges. Port-specific maps can be viewed by selecting a port in the Location dropdown menu.

Note: Data on recreational fishing can be found in Culture & Recreation.

Data Considerations

Original VTR data were obtained from NOAA NMFS Northeast Fisheries Science Center, with methodology, data processing and cartography provided by staff at Rutgers University. For information about methodology and interpretation of the data, see Creating Space for Community in Marine Conservation and Management: Mapping ‘Communities at Sea’ by Kevin St. Martin (Rutgers) and Julia Olson (NOAA). To produce the Communities at Sea maps, all data were aggregated to the community level, and none of the maps represent the fishing areas, or hot spots, of any individual fisherman or fishing vessel. Draft maps were reviewed and refined in consultation with fishermen in several ports. The following considerations and caveats guided and emerged from those conversations:

• These maps represent the locations and intensity of fishing during particular time periods. If these maps are considered during planning or permitting decision-making processes, it is critical to recognize that additional important fishing areas may not be represented, as locations frequently shift due to many factors such as market dynamics, regulatory changes, and rotational fishing strategies.
• These maps only show fishing conducted by vessels holding federal fishing permits. The maps do show a portion of state-licensed activity because many state-licensed vessels engaged in ocean fishing also hold federal permits and therefore submit VTRs. State-licensed fishing activity includes whelks (“conch”), striped bass, black sea bass, and lobster.
• Maps showing areas for fishing with fixed gear (pots, traps, gillnets) will tend to be more accurate than maps showing fishing using mobile gear (trawls, dredges), and maps showing single-day trips will tend to be more accurate than maps showing multi-day trips. This is because of the nature of the fishing activity and record-keeping regulations; fishermen are only required to report one geographic position (point location) per trip on VTRs unless switching to a new gear type or moving into a new statistical area.
• These maps can be supplemented with maps based on Vessel Monitoring System data (available for select federally managed fisheries); see the Vessel Activity subtopic of Commercial Fishing. Overlaying and comparing the VTR-based maps with VMS-based maps reveals substantial agreement between the two, and the VMS maps provide additional useful precision for some fisheries.
• Fisheries and fisheries data are complex, and there are many options for mapping fishing activity, each with strengths and weaknesses. These maps are intended as a starting point to help target and guide direct engagement and consultation with specific affected fishing communities during diverse ocean planning, permitting, and management decision-making processes.

For some types of decision making (e.g, detailed construction plans for energy infrastructure) much finer-scale information and data than can be obtained using either VTR or VMS data will be needed, ideally provided by fishermen.

Status

Communities at Sea data products were developed using data from 1996-2015. The Northeast and Mid-Atlantic Data Portal teams are working on new ways to depict information from Vessel Trip Reports in spatial data products.

Examples of Data

• Total Bottom Trawl < 65ft Activity 2011-2015
• Total Gillnet Activity 2006-2010
• Total Shrimp Activity 1996-2000

View Map: Examples of Data

Examples of Data

• CHATHAM, MA Longline Activity 2011-2015
• GLOUCESTER, MA Bottom Trawl <65 ft 2006-2010
• All Ports: Total Dredge Activity (2001-2005)

View Map: Examples of Data

View Complete List of Data in Data Explorer

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Subtopic

Vessel Activity

Vessel Activity data broadly characterize commercial fishing vessel activity in the Northeast based on Vessel Monitoring System (VMS) data from 2006 through 2019. The relative amount of vessel activity is indicated qualitatively from high (red) to low (blue). The National Marine Fisheries Service (NMFS) describes VMS as “a satellite surveillance system primarily used to monitor the location and movement of commercial fishing vessels in the U.S.” The maps do not necessarily distinguish between fishing activity, vessel transit, and other vessel activities. Some maps show vessel activity at less than four or five knots—a speed threshold that was determined with industry input to attempt to better highlight fishing areas. Nevertheless, those maps still likely show some non-fishing activities that occur at low speeds, such as processing catch, sorting, drifting, or idling in port. The most accurate interpretation of these maps is that they indicate relative levels of fishing vessel presence for federal fisheries that require VMS monitoring. The lack of historical data and relatively short timeframe of this map preclude consideration of historical fishing areas. It also does not illustrate more recent or future changes in fishing activity resulting from changing environmental and economic conditions, fisheries management, and other important factors.

Data Considerations

The limitations of the data used to produce these maps should be understood prior to interpretation of this map. The data provided by NMFS contained the day/month/year, the geographic coordinates of the vessel at the time of transmission, speed over ground, and the vessel’s declaration code, which signifies fishery plan, program within that plan, and associated area identifier or gear-type information. These data then were aggregated by combining all program codes within each fishery plan. VMS data is subject to strict confidentiality restrictions. Therefore, the map shows the density of vessel locations following the removal of individually identifiable vessel positions. The process of removing sensitive vessel locations followed the “rule of three” mandated by NMFS Office of Law Enforcement (OLE). The details of this filtering process vary between individual data products; see the metadata for each layer to see more detail on filtering processes used. A statistical method to normalize data was used on the subsequent density grids and data values represent standard deviations. While legends are consistent across products, values represent high or low areas of vessel activity specific to each dataset. This process can result in the maps showing vessel activity that seems anomalous, e.g. single data points in areas where multispecies fishing isn’t common, because three data points occur in a given 100m by 100m square. This is usually because of transit lines that overlap in a given cell while nearby cells contain less than three data points.

Status

Data through 2019 were updated and posted on Northeast Ocean Data in fall 2022, and they will continue to be updated as described in the 2016 Northeast Ocean Plan.

Examples of Data

• All VMS Vessels 2015-2019

View Map: Examples of Data

View Complete List of Data in Data Explorer

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