Freshwater and saltwater fisheries are important to both our culture and our economy. Fishing

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1 DECLINE IN SALTWATER FISH POPULATIONS (ECOLOGY AND HUMAN IMPACT ON THE ENVIRONMENT) 7 Freshwater and saltwater fisheries are important to both our culture and our economy. ing provides recreational opportunities and important food sources for society. There have been many debates about what kinds of policies should be implemented to safeguard our fisheries. According to the Florida and Wildlife Conservation Commission, Florida s marine fisheries provide over 2.5 million recreational anglers with sport fishing opportunities and over 15,000 commercial fishers with employment. Previously, it was a general belief that the oceans held an endless supply of fish. There are now many groups of people who think otherwise. Because these groups of people have different interests in the opportunities for fishing, they also have different ideas about the policies that should be enforced to protect the fish in the ocean. By protecting the fish, they are protecting their interests in fishing, including recreational fishing, economic impact (i.e., commercial fishing), and traditional lifestyle. Policies are generally designed to provide limitations by restricting opportunities. Restrictions can mean: reducing opportunities for businesses to grow by limiting the number of fishermen, the number of fish allowed to be caught, the size of fish to be caught, and the time of year that fish can be caught; preventing groups of people from practicing fishing as a part of their traditional lifestyles; impacting the general economy by reducing availability of (or by flooding the market with) fish; impacting the general economy by changing the costs for fishing and fishing supplies; and preventing groups of people from fishing for recreation. eries around the world claim that even with current policies, the fish populations are declining. For example, in 2005, the State of the World of eries and Aquaculture (SOFIA) released a statement that 3% of marine stocks were underexploited, 21% were moderately exploited, 52% were fully exploited, 16% were overexploited and the remaining 7% were recovering from being overexploited (due to strict policies) (Kourous 2005). The authors of this report blame the fish population decline on growing human populations and insufficient monitoring policies that would allow for this increased demand to be met without harming fish populations (i.e., limiting the numbers, the sizes, and the times that fish may be caught). In 2006, the Washington Post published an article describing a report from ecologists and economists claiming that at least 90% of fish species were below their historic maximum catch levels, due in part to the increase in commercial fishing and the inability of fish populations to resist environmental stresses created by the specific practices of commercial fishing (Eilin). SCIENTIFIC ARGUMENTATION IN BIOLOGY: 30 CLASSROOM ACTIVITIES 81 Copyright 2013 NSTA. All rights reserved. For more information, go to

2 7 DECLINE SECTION 1: GENERATE AN ARGUMENT IN SALTWATER FISH POPULATIONS In 2007 and 2008, the number of smolt (salmon migrating to the ocean) increased in the Sacramento River and in Alaska; however, the number of salmon returning to spawn substantially decreased, resulting in a ban on both commercial and recreational fishing of Chinook salmon (king salmon) for two years in California and in most of Oregon. The decline of salmon is blamed on the dams that have been built and the pesticides from farms bordering the rivers. Environmentalists assert that the salmon are unable to return upriver to spawn, and those that spawn in the lower river areas develop abnormalities caused by the pollutants that seep into the waters from farms. In an attempt to address the concern, biologists have been spawning salmon in hatcheries and releasing them into the oceans and rivers. Newspa reports claim that 90% of the Chinook salmon caught by fisherman in 2008 were from hatcheries rather than naturally spawned. Although several reports continue to express warnings about the decline of saltwater fisheries, in 2010 newspas and television reports claimed that the salmon numbers increased in Vancouver to numbers greater than any seen in over 100 years. In Florida, regulations for the past 20 years have included a strict management rule, known as a bag limit, of only one red drum fish mitted to be caught day by recreational fishermen. This regulation has recently been changed to allow for a two-fish bag limit (two fish son day). The Gulf red snap has reportedly increased, yet the recreational harvest season was reduced and the commercial quota was increased in The spotted seatrout have been strictly regulated by allowing anglers to only fish for them in certain parts of Florida during limited months of the year. The previous harvest prohibition for roundscale spearfish has recently been removed and is now a 250 fish season (i.e., the season closes once 250 of them are caught). These observations raise an interesting question: Is our saltwater fish population declining? If so, what policies would be most effective in slowing that decline? Because this is a complicated question that may have different answers for different regions, in this discussion we will be considering the fish populations around the Florida coast. You can use the following materials to generate your argument: Data tables that have been provided Information regarding policies and regulations that have been suggested or enforced Florida and Wildlife Conservation Commission ( National Oceanic and Atmospheric Administration (NOAA) education resources (www. education.noaa.gov/marine_life) With your group, determine if any of the fish populations are changing and if there is any particular group of people who should be regulated in fishing these populations. Be prepared to discuss what policies would be most appropriate for various groups of people who rely on the fish populations. Use the data that is provided to make inferences about the fluctuations in fish populations and the use of the fish for recreation, economic, and cultural purposes. You can use any resources online as well as any 82 NATIONAL SCIENCE TEACHERS ASSOCIATION Copyright 2013 NSTA. All rights reserved. For more information, go to

3 DECLINE IN SALTWATER FISH POPULATIONS 7 classroom supplies available to you to test your ideas. Make sure that you generate the evidence you will need to support your explanation as you work. You can record your method and any observation you make in the space below. With your group, develop a claim Figure 7.1. Components of the Whiteboard that best answers this question. Once your group has developed your claim, prepare a whiteboard that you can use to The Question: share and justify your ideas. Your whiteboard should include all the information Your Claim: shown in Figure 7.1. To share your work with others, we will be using a round-robin format. This means that one member of the group will stay at your workstation to share your groups ideas while the other group members will go to the other group one at a time in order to listen to and critique the arguments developed by your classmates. Your Evidence: Your Rationale: Remember, as you critique the work of others, you have to decide if their conclusions are valid or acceptable based quality of their claim and how well they are able to support their ideas. In other words, you need to determine if their argument is convincing or not. One way to determine if their argument is convincing is to ask them some of the following questions: How did you analyze or interpret your data? Why did you decide to do it that way? How do you know that your analysis of the data is free from errors? Why does your evidence support your claim? Why did you decide to use that evidence? Why is your evidence important? How does your rationale fit with accepted scientific ideas? What are some of the other claims your group discussed before agreeing on your claim, and why did you reject them? References Eilin, J. The Washington Post World s Supply Running Out, Researchers Warn. November 3. Kourous, G., Depleted fi sh stocks require recovery efforts. Food and Agriculture Organization of the United Nations. SCIENTIFIC ARGUMENTATION IN BIOLOGY: 30 CLASSROOM ACTIVITIES 83 Copyright 2013 NSTA. All rights reserved. For more information, go to

4 DECLINE IN SALTWATER FISH POPULATIONS: What Is Your Argument? In the space below, write a one- to three-paragraph argument to support the explanation that you think is the most valid or acceptable. As you write your argument, remember to do the following: State the explanation you are trying to support Include appropriate and relevant evidence Make your rationale for including the evidence explicit Organize your pa in a way that enhances readability Use a broad range of words including vocabulary that we have learned Make sure your writing has an easy flow and rhythm Correct grammar, punctuation, and spelling errors 84 NATIONAL SCIENCE TEACHERS ASSOCIATION Copyright 2013 NSTA. All rights reserved. For more information, go to

5 Table 7.1. Annual Standardized Commercial Catch Rates of Select Along the Florida Atlantic Coast from 1999 to 2009 (Average Pounds Trip) Atlantic Coast, Commercial Landings Rates (Average Pounds Trip) Catch Atlantic Croaker Bluefish Flounders Striped mullet Sheepshead Red Drum N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A Table 7.2. Annual Standardized Commercial Catch Rates of Select Along the Florida Gulf Coast Between 1999 and 2009 (Average Pounds Trip) Gulf Coast, Commercial Landings Rates (Pounds Trip) Catch Atlantic Croaker Bluefish Flounders Striped mullet Sheepshead Red Drum N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A SCIENTIFIC ARGUMENTATION IN BIOLOGY: 30 CLASSROOM ACTIVITIES 85 Copyright 2013 NSTA. All rights reserved. For more information, go to

6 7 DECLINE SECTION 1: GENERATE AN ARGUMENT Table 7.3. Annual Standardized Recreational Catch Rates of Select Along the Florida Atlantic Coast Between 1999 and 2009 (Average Number of Trip) IN SALTWATER FISH POPULATIONS Atlantic Coast, Recreational Landings Rates (Average Trip) Catch Atlantic Croaker Bluefish Flounders Striped Mullet Sheepshead Red Drum Table 7.4. Annual Standardized Recreational Catch Rates of Select Along the Florida Gulf Coast Between 1999 and 2009 (Average Number of Trip) Gulf Coast, Recreational Landings Rates (Average Trip) Catch Atlantic Croaker Bluefish Flounders Striped Mullet Sheepshead Red Drum NATIONAL SCIENCE TEACHERS ASSOCIATION Copyright 2013 NSTA. All rights reserved. For more information, go to

7 DECLINE IN SALTWATER FISH POPULATIONS 7 Table 7.5. Annual Observations of Young of the Year (YOY) of Select Along the Florida Atlantic Coast Between 1999 and 2009 (Number Counted) From ery- Independent Monitoring Sets That Captured Atlantic Coast YOY Catch Atlantic Croaker Bluefish N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A Flounders Striped Mullet Sheepshead Red Drum Table 7.6. Annual Observations of Post-Young of the Year (YOY) of Select Along the Florida Atlantic Coast Between 1999 and 2009 (Number Counted) From ery- Independent Monitoring Sets That Captured Atlantic Coast Post-YOY Catch Atlantic Croaker Bluefish N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A Flounders Striped Mullet Sheepshead Red Drum SCIENTIFIC ARGUMENTATION IN BIOLOGY: 30 CLASSROOM ACTIVITIES 87 Copyright 2013 NSTA. All rights reserved. For more information, go to

8 7 DECLINE SECTION 1: GENERATE AN ARGUMENT IN SALTWATER FISH POPULATIONS Table 7.7. Annual Observations of Young of the Year (YOY) of Select Along the Florida Gulf Coast Between 1999 and 2009 (Number Counted) From ery-independent Monitoring Sets That Captured Gulf Coast YOY Catch Atlantic Croaker Bluefish N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A Flounders Striped Mullet Sheepshead Red Drum Table 7.8. Annual Observations of Post-Young of the Year (YOY) of Select Along the Florida Gulf Coast Between 1999 and 2009 (Number Counted) From ery-independent Monitoring Sets That Captured Gulf Coast Post-YOY Catch Atlantic Croaker Bluefish N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A Flounders Striped Mullet Sheepshead Red Drum NATIONAL SCIENCE TEACHERS ASSOCIATION Copyright 2013 NSTA. All rights reserved. For more information, go to

9 DECLINE IN SALTWATER FISH POPULATIONS 7 Table 7.9. Information About Selected Populations Found Around the Florida Coast Species and Appearance Catch Information 2009 Characteristics and Regulations Atlan c Croaker Micropogonias undulatus a. Commercial landings (pounds) Food (Prey): The young-of-the-year 6 eat polychaetes, copepods, and mysids; adults eat crustaceans, molluscs, and smaller fi sh Predators: Striped bass, southern flounder, sharks, spotted seatrout, larger Atlantic croaker, red drum, sheepshead, bluefi sh, and weakfi sh Habitat: Young fi sh are found in estuaries and older fi sh (2 3 yrs) in deep offshore waters during the winter months and in bays and estuaries during the spring, summer, and fall. b. Recreational landings (numbers) Behavior: Spawning occurs offshore in the fall. They turn bronze or yellow during spawning. Regulations: No specifi c regulations for recreation or commercial fi shing (continued) SCIENTIFIC ARGUMENTATION IN BIOLOGY: 30 CLASSROOM ACTIVITIES 89 Copyright 2013 NSTA. All rights reserved. For more information, go to

10 7 DECLINE SECTION 1: GENERATE AN ARGUMENT IN SALTWATER FISH POPULATIONS Table 7.9. Information About Selected Populations Found Around the Florida Coast (continued) Species and Appearance Catch Information 2009 Characteristics and Regulations Bluefish Pomatomus saltatrix a. Commercial landings (pounds) Food (Prey): Opportunistic feeders that will eat anything that is smaller and available Predators: Larger bluefi sh; birds feed on the young; sharks, tuna, and billfi sh feed on the larger bluefi sh Habitat: Young usually are inshore during the spring and summer and move offshore to join adults during the fall and winter. They migrate to Florida during the winter. b. Recreational landings (numbers) Behavior: Travel in large schools following baitfi sh. They are usually about the same size in schools because they are cannibalistic. Spawning occurs offshore in spring and summer. Regulations: Size limit: 12 in. fork length (FL) measure (the tip of snout to fork of tail) Commercial: Trip limit/bag limit: Atlantic north of Monroe County/7,500 lbs. vessel day Closed season: none Restricted Species Endorsement mit 3 No more than one net set vessel unless varied in mesh size Limitations to length size of nets Recreational: Trip limit/bag limit: 10 son day Must remain whole until ashore (continued) 90 NATIONAL SCIENCE TEACHERS ASSOCIATION Copyright 2013 NSTA. All rights reserved. For more information, go to

11 DECLINE IN SALTWATER FISH POPULATIONS 7 Table 7.9. Information About Selected Populations Found Around the Florida Coast (continued) Species and Appearance Catch Information 2009 Characteristics and Regulations Gulf Flounder Paralichthys albigu a a. Commercial landings (pounds) Food (Prey): The young are bottom feeders eating shrimp, crabs, and small fi sh; adults feed on schooling menhaden, bay anchovy, pinfi sh, grunts, pigfi sh, Atlantic croaker, and mullets. Predators: Sharks, oyster toadfi sh, and striped bass Habitat: Found inshore on sandy or muddy bottoms and in tidal creeks; occasionally on near-shore rocky reefs b. Recreational landings (numbers) Behavior: They lie on the bottom often partially covered by sand or mud waiting for prey to come near, and then they strike suddenly. They hatch with a typical fi sh form, but the right eye migrates over to the left side early in life. They spawn offshore. Regulations: Size limitations: 12 in. in total length (TL) (the measure from tip of snout to fork of tail) Commercial: Trip limit/bag limit: incidental bycatch (accidental or unintentional catching while fi shing for other species or organisms) Closed season: none Restricted Species Endorsement mit; beach and cast net allowed; hook and line allowed; spearing only in Volusia County but not with more than three prongs; must remain in whole condition until landed ashore; no multiple hooks mitted in catching Recreational: Trip limit/bag limit: 10 son day Spearing is OK; snatching prohibited; must remain whole until landed ashore (continued) SCIENTIFIC ARGUMENTATION IN BIOLOGY: 30 CLASSROOM ACTIVITIES 91 Copyright 2013 NSTA. All rights reserved. For more information, go to

12 7 DECLINE SECTION 1: GENERATE AN ARGUMENT IN SALTWATER FISH POPULATIONS Table 7.9. Information About Selected Populations Found Around the Florida Coast (continued) Species and Appearance Catch Information 2009 Characteristics and information Red Drum Sciaenops ocellatus a. Commercial landings (pounds) This fish is not a commercial fish. Therefore there is no data for geographical landings Recreational landings (numbers) Food (Prey): The young eat copepods, mysid shrimp, and amphipods; adults eat menhaden and anchovies in the winter and spring; adults eat crabs and shrimp in the summer and fall. Predators: Larger fi sh, birds, bottlenose dolphin Habitat: In the winter, they are found in sea grass, over muddy or sand bottoms, or near oyster bars or spring fed creeks. Behavior: Young remain inshore until they reach roughly 30 inches (four years) and then they migrate to near-shore populations. They produce tens of millions of eggs from August through December in passes, inlets, and lagoon estuaries. Regulations: Commercial: prohibited completely Recreational: Size limitations: not less than 18 in. or more than 27 in. Trip limit/bag limit: two son day in the northern regions and one son day in the southern regions Must remain in whole condition until landed ashore; measured as total length from the mouth to the tip of tail; single hook gear only; gigging, spearing, and snatching are prohibited (continued) 92 NATIONAL SCIENCE TEACHERS ASSOCIATION Copyright 2013 NSTA. All rights reserved. For more information, go to

13 DECLINE IN SALTWATER FISH POPULATIONS 7 Table 7.9. Information About Selected Populations Found Around the Florida Coast (continued) Species and Appearance Catch Information Characteristics and Regulations Sheepshead Archosargus probatocephalus a. Commercial landings (pounds) Food (Prey): The young eat zooplankton, polychaetes, and larval chironomids; large juveniles and adults eat blue crab, young oysters, clams, crustaceans, algae, and small fi sh. Predators: Bull shark, red drum, and striped mullet Habitat: An inshore fi sh found around oyster bars, seawalls, and tidal creeks Behavior: They migrate near shore during late winter and early spring for spawning. They are fractional spawners (only laying a portion of their eggs at a time). b. Recreational landings (numbers) Regulations: Size limitations: 12 in. TL Commercial: Trip limit/bag limit: incidental bycatch (accidental or unintentional catching while fi shing for other species or organisms) Closed season: none Restricted Species Endorsement mit; beach and cast net allowed; hook and line allowed Recreational: Trip limit/bag limit: 15 son day Must remain whole until landed ashore; no snatching (continued) SCIENTIFIC ARGUMENTATION IN BIOLOGY: 30 CLASSROOM ACTIVITIES 93 Copyright 2013 NSTA. All rights reserved. For more information, go to

14 7 DECLINE SECTION 1: GENERATE AN ARGUMENT IN SALTWATER FISH POPULATIONS Table 7.9. Information About Selected Populations Found Around the Florida Coast (continued) Species and Appearance Catch Information 2009 Characteristics and Regulations Striped Mullet Mugil cephalus Food (Prey): phytoplankton, zooplankton, benthic microalgae, detritus or inorganic sediment particles. Predators: larger fi shes such as snook, spotted seatrout, red drum, hardhead catfi sh, southern flounder, bull shark, and alligator gar. Also birds such as osprey and brown pelican. Habitat: Found inshore Behavior: Adults migrate offshore in large schools to spawn. Young migrate inshore at about 1 inch in size, moving far up tidal creeks. These fi sh are frequent leas. Regulations: Commercial: Statewide Size limits: 11 in. FL Only cast nets (no more than two vessel) and hook and line gear Harvest is prohibited seaward of the 3-mile line (Gulf and Atlantic) and seaward of the Everglades National Park line in Florida Bay Commercial: By Area Pinellas County (Tampa Bay): Trip limit/bag limit: fi ve son day or vessel Season closed: October to February Manatee County Trip limit/bag limit: 50 mullet son or vessel day Season closed: November to February Charlotte County Trip limit/bag limit: 50 mullet son or vessel day Season closed: November to February Charlotte County (Punta Gorda area) Trip limit/bag limit: 50 mullet son or vessel day Season closed: November to March No night harvesting (6 p.m. 6 a.m.) Recreational: Size limit: none Trip/bag limit: 50 day son (aggregate: count includes sum of all mullet caught); 100 aggregate vessel day from February to August; 50 aggregate vessel day during September to February (continued) 94 NATIONAL SCIENCE TEACHERS ASSOCIATION Copyright 2013 NSTA. All rights reserved. For more information, go to

15 DECLINE IN SALTWATER FISH POPULATIONS 7 Table 7.9. Information About Selected Populations Found Around the Florida Coast (continued) Reference Florida and Wildlife Conservation Commission. Saltwater fi sh. Florida and Wildlife Conservation Commission. SCIENTIFIC ARGUMENTATION IN BIOLOGY: 30 CLASSROOM ACTIVITIES 95 Copyright 2013 NSTA. All rights reserved. For more information, go to