The Marine Resource Administration (MRA) has initiated the Sponge Crab Sighting Survey for the gathering of data on egg bearing female blue crabs found in New Jersey. 

If you see a female blue crab carrying a sponge of eggs, MRA would like to know about it. 

Blue Crab Information

What is a sponge?

A sponge contains millions of eggs that ranges in color from orange to brown or almost black as they develop in early spring to summer. A sponge may be found “spilling out” from the underside of a crab, held between the crab’s body and apron.

Behavior

The behavior of blue crabs in NJ waters differs from that of the Chesapeake Bay blue crabs. One factor being the colder waters experienced in New Jersey estuaries. Cold water increases the resource demands on a blue crab and is reflected in the on average smaller size of NJ crab in comparison to those found in the Chesapeake Bay. A torpor behavior, relatively unique to NJ blue crabs, is seen in populations and is similar to a bear’s hibernation. The crab will bury itself in the sand partially during the winter and reduce energy and resource consumption during this time. This extreme survival behavior impacts the overall growth of the crab but especially in females who require large percentages of resources to produce egg sponges. The MRA is seeking data on where, when, and how close to spawning NJ female blue crabs are to better understand the environmental demands on NJ female spawning blue crabs.

Survey

The MRA intends to use the information obtained from the survey to build upon its current understanding of New Jersey blue crab spawning behavior, to establish and maintain sighting records, to enlist and incorporate more citizen data collection, and to be able to follow trends and track changes.

Your Input Matters

Every report helps further the understanding of New Jersey’s unique blue crab spawning behavior. Any sightings can be reported here.

The MRA thanks you for your participation.

***It is to be noted that it is illegal in the state of New Jersey to have in your possession any sponge or recently bearing sponge crab. All crabs carrying or recently bearing a sponge of eggs should be released to the water immediately.