Gulf of Maine Cooperative Bottom Longline Survey Database

This database is for a bottom longline (fixed gear) survey executed in the western and central Gulf of Maine targeting complex rocky habitats. The survey is operated from collaborating commercial fishing vessels, and deploys 1 nm sets of traditional 'tub trawl' bottom longline groundfish gear (1000 hooks). Longline gear is deployed at randomly selected stations within selected NEFSC bottom trawl survey (BTS) strata in the western and central Gulf of Maine during the spring and autumn, overlapping temporally with the NEFSC seasonal BTS in that region. Specific ‘hard’ and ‘smooth’ bottom sub-strata were chosen within the BTS strata based on predictive habitat maps that have identified complex habitat at a spatial resolution of @1.3km2 (Manderson et al. 2011). The total number of longline stations are allocated by the overall area of each stratum, as done in the NEFSC BTS, and stations randomly distributed in the ‘hard’ and ‘smooth’ sub-stratum within each stratum. Each set is made for 2 hours, with gear deployed 1 hour prior to the estimated time for slack tide at that location. The ambient current is monitored with an instrument with an accelerometer (also equipped with a compass and thermometer), which is attached to the mainline on each end of the longline (by the last hook). Temperature-depth probes are deployed on the anchor at each end of the longline. Catch weights, fish lengths, and other biological data are collected for all species following standard survey protocols. Biological sampling (for age and reproductive data) is collected for a subset of species and sizes relative to the BTS’s request protocols to fill in data on uncommon species, and less common sizes (i.e. larger individuals) of key groundfish.

The objective of this survey is to provide important information for several species that are not well sampled in BTS or those that are not caught in substantive numbers (targeted) by commercial or recreational fisheries to inform management, Endangered Species Act (ESA) listing decisions, and conservation plan measures. These include cusk, which is a candidate species under the ESA and a data poor stock, as well as Atlantic Wolffish, Atlantic Halibut, and Thorny Skate, which are all NOAA Species of Concern. This survey is designed to increase sampling opportunities for all of these species. Catch and biological data from this survey provides useful supplemental data and indices for other groundfish including white hake, barndoor skate, red hake, spiny dogfish, haddock, Atlantic cod, and smooth skate.

A bottom longline (fixed gear) survey executed in the western and central Gulf of Maine focused on areas of complex rocky habitat that are not readily sampled by mobile trawl gear. This survey addresses concerns about the limited data of specific species in hard bottom habitats for important groundfish stocks collected on other surveys. It particularly enhances data collection for several data poor and depleted stocks that are specifically associated with rocky habitat.

NEFSC Data Access Procedure:

1. Formal request in writing usually to the data owner/contact or Center Director;

2. Requester is contacted by data owner to review and verify the request content and details for data delivery options.

3. If data is confidential then owner will determine if the data may be released to the requester;

4. If data can be released, the data is downloaded and packaged for delivery electronically; or the requester may be directed to where the data is available online.

NEFSC Data Access Constraint:

If data is stored on an internal NEFSC network, the requester may not have direct access to query the data unless they are also authorized for network access.

Vessel locations, fishing operational data, and aggregate fish weight data are recorded using the FLDRS v3.1 software. Aggregate fish weights are initially recorded on data sheets, and subsequently summed in excel and entered into FLDRS software. Fish length data are captured from wireless measuring boards on handheld Allegro field PC's with windows mobile using CEWedge software. The length data are recorded with DataTrawler v1.0 software written in visual basic, which outputs the data in a Microsoft access database file (.accdb). Biological data are recorded by hand and entered on shore into excel before loading into the Oracle database. Star Oddi temperature-depth sensors are downloaded using the Sea Star software v7.02 and exported in a .dat file.

Vessel locations are taken from the vessel's GPS and recorded at ±0.0001°. Fish weights are taken using Merel motion compensated scales, and recorded ±0.1 kg for aggregate catch weights and ±0.01 kg for individual fish weights. Aggregate fish weights are for undifferentiated sexes for all species, except spiny dogfish weights are sex specific. Fish lengths are collected using Latitude 42 boards with Haglof wireless sensors, and they are recorded at ±1 cm precision. Temperature and depth data at the anchors are recorded with Star Oddi sensors with a precision of ±0.01m and ±0.01°C. Current flow is recroded at a ±0.01 m/s, direction ±0.01° true north, and temperature ±0.001°C. Fish are identified to the species level. Sex and maturity are characterized using the standard survey macroscopic schemes. Fish ages are reported to the nearest year with the same protocols and precison as in the bottom trawl survey database.

Data collection and auditing are ongoing. The status of auditing should be checked before the use of any data.

Hand entered data is confirmed while on the vessel and secondarily in post cruise processing. Limited data auditing procedures are available while at sea. Standardized data auditing to identify erroneous entries or extreme values are conducted during post cruise processing and import of data. Morphometric data are checked against standard species specific regressions. Some unique data types still have auditing procedures under development (e.g. current data).

Data will be archived once a solution for archiving relational data sets is defined

Archival of source data preserving unaltered collected data, Scheduled backups, Remote storage backups, Password protection

The survey data began to be collected in the field in April 2014. A dedicated database began to be designed for storing the data starting in fall 2014.