Conditions in the Hawai‘i longline fishing ground


The maps below depict sea surface temperature (SST) climatologies (1985-2019) and anomalies (2020) in the Hawai‘i longline fishing ground (area indicated by the white box on the maps).
We used the NOAA CoralTemp product to compute mean SST in the region.

Climatology of SSTs in the longline fishing ground
SST anomalies in the longline fishing ground




You can click and drag to zoom in on a specific portion of the graphs, double click to zoom out, or use the slider below the graph to select a specific time period.







The maps below depict chlorophyll a concentration climatologies (1998-2019) and anomalies (2020) in the Hawai‘i longline fishing ground (area indicated by the white box on the maps) from the ESA CCI v5.0 product, which merges several sensors over time to produce a consistent long-term time-series.
Higher chlorophyll a concentrations indicate more productive waters.

Climatology of chlorophyll a concentration in the longline fishing ground
Anomalies of chlorophyll a concentration in the longline fishing ground




You can click and drag to zoom in on a specific portion of the graphs, double click to zoom out, or use the slider below the graph to select a specific time period.







The Norht Pacific SubTropical Front (STF) is marked by the 18°C SST isotherm and the Transition Zone Chlorophyll Front (TZCF) by the 0.2 mg chl.m-3 isopleth. They roughly mark the northern boundary of the North Pacific Subtropical Gyre as well as the northern extent of the Hawai`i-permitted longline fishery. The STF is targeted by the swordfish fishery. Additionally, both the STF and TZCF are used as migration and foraging corridors by both commercially-valuable and protected species. Both fronts migrate meridionally seasonally and their positions are impacted by the phase of ENSO. Due to significant seasonal variation, the climatology (SST: 1982 – 2015, Chl: 2003 – 2015) and anomaly (2016) are presented for the first quarter of the year only, when the swordfish fishery operates.

Positions of the Subtropical Front and Transition Zone Chlorophyll Front
The climatological (solid) and 2016 (dashed) positions of the STF (red) and TZCF (blue) in the first quarter of the year (Jan – Mar).
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