On Friday October 25, the final quarterly beach seine was deployed for the Colorado Lagoon’s first year of
environmental monitoring. A beach seine is a method of fishing that uses a net
hung vertical in the water with the bottom edged weighted and the top buoyed by
floats. Seines have been used widely though out history and today scientists use
this method to help identify spatial and temporal changes in fish assemblages.
There are possible causes of observed changes in the assemblages with include
natural phenomena (climate), pollution, habitat degradation and restoration!
The Friday beach seine was deployed in three areas, two outside the
reserve and one with in the reserve. The first seine we caught tons of baby
California Killifish (Fundulus parvipinnis). This species is a coastal fish that occurs in shallow bays, estuaries
and marshes. They can tolerate a wide range of salinities, oxygen levels and pollution.
The second seine was inside the reserve, where we caught over 500 adult and baby
California Killifish! We also caught several Topsmelt (Atherinops affinis), this species is also common in estuaries and can tolerate drastic swings in water salinity! The most exciting surprise of this seine was the Two-spotted Octopus (Octopus
bimaculoides). This was the first octopus ever caught in one of Colorado Lagoon’s beach seines! Two-spotted
Octopus is named for its obvious blue spots located behind its eyes. They can grow up to a two foot arm span and the female can lay up to 150,000 eggs. They female will brood continuously for 2-4 months, she does not feed during this
time and then dies around hatching time. The young remain on the bottom after hatching and have a life span of 2-3 years!
The third beach seine deployed was across the bridge and we found a Striped Kelpfish (Gibbonsia metzi)! This species can be found in tide pools and kelp beds down to a depth of 9 meters.
Fridays beach seines and the previous seines in the Colorado Lagoon have laid the base line survey for future seines to be