Striped Mullet

15.98% = DEPLETED

How It’s Calculated

FINDEX is a novel way to gauge whether the status of a fish population is trending up or down. Management of most fish species in North Carolina is guided by stock assessment models developed by various groups of scientists. The calculations in our FINDEX metric measure the gap between the desired condition of a fish stock (the Target reference value) and the existing condition (the most recent data year in the model called the Terminal value) as determined in each stock assessment. The gaps between Target and Terminal values are reported as ratios.

For example, if the Target and Terminal values are the same, there would be no gap, and the ratio would be 1.0. The multiplier on our FINDEX barometer would set the FINDEX value at 100% in this example and assign a stock status designation of “Stable.” Categories on the FINDEX barometer are measurable as they track the extent of the gap either above or below the “Stable” designation.

For Striped Mullet, the FINDEX gap assessment compared Target and Terminal values of Fishing Mortality (F_35%) and Spawning Stock Biomass (SSB_35%) from the most recent stock assessment model developed by the NC Division of Marine Fisheries. The Terminal year in the stock assessment model was 2019.

Here's the FINDEX formula used for Striped Mullet:

(0.619 x 0.258) x 100 = 15.98%
FINDEX = 15.98% for 2019
15.98% = DEPLETED

What Does Depleted Mean?

A FINDEX designation of “Depleted” is assigned to any stock with a value less than 50%. Depleted indicates that the stock is severely impaired. Striped Mullet are being removed too rapidly, and the estimated number of spawning females in the population (Spawning Stock Biomass) is well below threshold and target levels for a sustainable fishery.

Note there is a significant time lag associated with updates to stock assessments for many of North Carolina’s fisheries. Periods between updates are usually 5 years, and sometimes much longer. For this reason, FINDEX calculations may not accurately describe current conditions – instead, FINDEX evaluates the most recent scientific data available. Striped Mullet data has been updated through 2019.

FINDEX Stock Status Over Time

The stock assessment model for Striped Mullet provides point estimates of Fishing Mortality and Spawning Stock Biomass for each year covered in the data set. We’ve compared the Target reference values to these annual point estimates and calculated the ratios (gaps) for each data year from 1985–2019.

Applying the FINDEX gap assessment to the entire time series provides the following stock status trendline:

How Do We Get To World-Class?

FINDEX can also be used to determine when a population has reached “World-Class” status. Because FINDEX factors performance of both Fishing Mortality and Spawning Stock Biomass into the metric, multiple combinations of these values could potentially lead to a World-Class designation.

Striped Mullet Target values for Fishing Mortality (0.26) and Spawning Stock Biomass (1,019 metric tons) have been established by the management agencies. The existing estimates (2019 values) are 0.42 and 263 metric tons. Under one potential scenario, if Fishing Mortality was to drop to the Target value and Spawning Stock Biomass was to increase to 2,100 metric tons, then the FINDEX value would exceed 200% on our barometer. The vision of the NC Marine & Estuary Foundation is to see our coastal stocks exceed Target expectations as we pursue World-Class fisheries and thriving coastal economies.

Commercial Trends

The graph below illustrates commercial trends for Striped Mullet from 1990 through 2022. In 2022, commercial fishers harvested 2,720,092 pounds of Striped Mullet valued at $2,118, 988. Supporting data was sourced from the North Carolina Department of Environmental Quality.

Recreational Trends

Striped Mullet is not a popular target species for recreational anglers in North Carolina. However, recreational anglers will use cast nets to collect juvenile Striped Mullet (called “Finger Mullet”) as bait to catch other species. Data collection programs rarely encounter coastal anglers fishing for Striped Mullet, so the available data is scattered and imprecise.

Did you know?

White Mullet can be differentiated from Striped Mullet by their lack of stripes and the presence of a distinct gold spot on the gill cover.
Adult Striped Mullet migrate in the fall from NC freshwater and estuarine waters to the Atlantic Ocean to spawn.
Up to 4 million eggs have been observed in a single female Striped Mullet.
Striped Mullet are capable of full osmoregulation, meaning they can tolerate salinities ranging from entirely freshwater to full seawater strength.
The diet of Striped Mullet is primarily bottom muck and surface scum – feeding habits of fishes referred to formally as “herbivorous detritivores”.
Mullet “jump” to move air into the upper portion of the pharynx to aid respiration.

Harvest Seasons for Striped Mullet

The recreational limit for Striped Mullet is currently 200 fish per day (Striped Mullet and White Mullet combined). There is no size limit as harvest is focused on small fish used as bait.
No annual quota exists for commercial landings of Striped Mullet. Proclamations for Striped Mullet can be found here.

What’s Next?

As our team diligently refines FINDEX, we are committed to delivering the most recent stock status updates for North Carolina’s diverse finfish species. Subscribe below to receive a stream of inshore insights and stay current with our coastal initiatives.