Fish play a variety of roles in aquatic ecosystems. Some are predators of other aquatic life, while other feed on plant material. Still others scavenge or feed on phytoplankton. Some species deposit eggs in special nests while others have live young. Fish also exhibit a wide range of behaviors and have many different characteristics and adaptations. While some fish species are better known or seen more often, ALL fish play important roles in our aquatic ecosystems. The first step in understanding our local fish, is to define everything we can about the local water in which they live and why they live here. By the end of this class, our job will be to create a class reference manual (or what scientist call a field guide) for use in our future projects.
We live and work in the Galveston Bay area and some of you may even live on Galveston Island. Galveston Bay is actually made up of four smaller bays, Trinity, Galveston, East, and West. So when we use the term Galveston Bay we are actually talking about all four of these bays.
According to Texas A&M University Galveston Campus, Galveston Bay supports a population of finfish totaling more than 162 species. http://gbic.tamug.edu/gbayfastfacts/gbff_menu.html You may ask yourself, “Why do I care about all this?” Galveston Bay contributes 1/3 of Texas' commercial fishing income. According to a study completed by NOAA, in 2009 this amounted to $157, 916 dollars and over 9,000 jobs. Maybe some of your parents are employed in the fishing industry or jobs that support the fishing industry. A couple examples of this may be someone who works at an Academy store or works in a restaurant that sells seafood. http://www.st.nmfs.noaa.gov/st5/publication/econ/2009/gulf_TXtables_econ.pdf
Galveston Bay is connected to the Gulf of Mexico via 3 major waterways. Rollover Pass which is located on Boliver Island, Houston Ship Channel which lies between Galveston and Boliver, and the San Luis Pass which lies between the west end of Galveston and Freeport. These three passes allow fish to travel back and forth between the bays. This plays an important part for fish migration. Fish migration plays an important role in the health and sustaining the bay system. Some fish spend their entire life in the Bay, while others come in from the Gulf as newly hatched young and stay only a couple of years until they mature. Fish migration happens for two major reasons: laying and spawning of their eggs (or reproduction) and food.
Spawning grounds are usually located far from areas where the adult fish gather food. The distance between the two areas help ensure survival of the baby fish. Remember, if you are the small fish, you may be eaten by a larger fish. Being far away from feeding areas of the larger fish or adult fish lessons the likelihood that they will be eaten. Also baby fish have much different diets that the adult fish. They need to be in a habitat that provides them with the proper amounts and types of nutrient in order for them to survive. This may include plankton or other smaller types of fish. The following clip talks about the flying fish and their drive to reproduce.
Many species of saltwater fish undertake migrations in order to travel to areas where there is more food. Some species of ocean-dwelling fish feed on phytoplankton which is microscopic plants in the ocean. Like plants on land, phytoplankton growth differs according to season. Once food sources becomes scarce in one area, many fish migrate to warmer waters where there is more abundant plant growth. Some species of fish eat other, smaller phytoplankton-eating fish. These larger fish often migrate to follow the smaller fish. The next clip show a school of fish in what is called a feeding frenzy. The have located a group of smaller phytoplankton-eating fish (bait fish) and are attacking.
Habitats are homes where fish live. Fish live where conditions are correct for their survival. Changes in these conditions, force fish to move or become possibly become endangered if they can not adapt quickly. Can you think of a recent situation where many habitats were threatened.
So let’s review: Galveston Bay supplies 1/3 of Texas’s Commercial Seafood Income and is comprised of 4 smaller bays. The entire system is connected to the Gulf of Mexico by 3 made cuts or passes. Galveston Bay supports 162 different finfish. These finfish can migrate can migrate back and forth from the bay to deeper waters of the Gulf of Mexico through the passes. They migrate for two main reasons – reproduction and feeding. The bay provides a habitat that is conducive for the survival of smaller fish that will eventually return to the Gulf as adults.
Interview with a Fish! “Reel” Field Guide
Galveston Bay You Are Here http://www.gbep.state.tx.us/about-galveston- bay/geography.asp
Galveston Bay Galveston Bay contributes 1/3 of Texas commercial fishing income Galveston Bay supports a population of finfish totaling more than 162 species.
Quick Check How many smaller bays make up Galveston Bay? 4 – Trinity, East, West, and Galveston Galveston Bay has no impact on the Texas economy? False – 1/3 of Texas commercial fishing income is from Galveston Bay How many different types of finfish does Galveston Bay support? 162
Migration Some fish spend their entire life in the Bay, while others come in from the Gulf as sac fry (newly hatched young) and stay only a couple of years until they mature. Reproduction: Spawning Lay Eggs Feed
Reproduction Spawning grounds are usually located far from areas where the adult fish gather food Distance between feeding and breeding areas helps ensure the survival of the baby fish Baby fish have different diets than adult fish
Quick Check What are the two main reasons fish migrate? 1 – Reproduction 2 – Feeding
Habitat Correct Conditions Changes in conditions of the habitat can endanger species Bonus – Can you think of a situation recently where habitats were threatened.
Final ReviewGalveston Bay Fish Population• 1/3 Texas 162 Different types of Commercial Finfish Seafood Income• Made up of 4 Migration: smaller bays •Reproduction •Feeding• 3 Connections to Habitat Gulf of Mexico