The number of US fisheries deemed "overfished" climbed in 2018, with West Coast king and coho salmon, Gulf of Maine Atlantic mackerel and Atlantic big eye tuna among the species added.

The National Oceanic and Atmospheric Administration (NOAA) Report to Congress on the Status of US Fisheries, released Friday, surveys fisheries in US territorial waters annually to determine the status of stocks deemed troubled under NOAA's management guidelines.

In its report, NOAA designates fisheries under excessive pressure as either "overfished" or subject to "overfishing."

A stock being "overfished" has a population size that is too low, jeopardizing its ability to reach maximum sustainable yield (MSY), or a long-term sustainable catch. Under NOAA's definition, an "overfished" stock is impacted not just by harvesting, but other environmental factors as well.

The majority of both "overfished" stocks and stocks subject to "overfishing" have limited commercial impact.

This year, an additional nine stocks were added to the "overfished" list, including the Sacramento River and Klamath River fall chinook runs, two Washington Coast coho salmon stocks, Atlantic bigeye tuna and the Atlantic mackerel stock in the Gulf of Maine.

The number of stocks subject to "overfishing," which indicates harvest pressure on the stock that exceeds the MSY, fell last year, and the number of stocks on the overfishing list remains near all-time lows.

Species including Western & Central Pacific bigeye tuna and Gulf of Mexico greater amberjack fell off the list. Others were added, however, including Eastern Pacific yellowfin tuna and two Gulf of Mexico snappers. Another, the smooth skate stock in the Gulf of Maine, on the "rebuilt" list.

Under the US Magnuson Stevens Act management framework, fishing councils develop management measures to end overfishing and rebuild struggling stocks.