Recommended
More Related Content
What's hot
What's hot (19)
Similar to Fisheries and Climate Change
Similar to Fisheries and Climate Change (20)
Recently uploaded
Recently uploaded (20)
Fisheries and Climate Change
- 1. Steve Luell AmeriCorps Watershed Ambassador WMA 14 – Mullica River
- 2. • A partially enclosed coastal body of water where saltwater from the ocean mixes with freshwater from rivers, creeks and streams • Sheltered from the full force of the waves and winds • Important nurseries for many species of fish and shellfish Steve Luell
- 3. Ichthyoplankton are larval fish found in the water column • “Ichthyo” – fish • “Plankton” – small organisms drifting or floating in the water RUMFS
- 4. • Evaluate recruitment success • Recruitment refers to when juvenile fish survive to a size where they can be targeted by commercial and recreational fishermen • Largely affected by mortality during the larval stages
- 5. • Sampling conducted weekly at Little Sheepshead Creek since 1989 • During the night on the incoming tide • Three consecutive 30 minute tows using a 1 mm mesh plankton net
- 7. Photos by Chris Filosa
- 8. Photos by Chris Filosa
- 9. Photos by Chris Filosa
- 10. Chris Filosa Photos by Steve Luell
- 12. • Samples preserved in 95% ethanol for later identification • Preserved samples are sorted and identified to species using a dissecting microscope Chris Filosa
- 13. RUMFS
- 14. RUMFS
- 15. RUMFS
- 16. RUMFS
- 17. RUMFS
- 18. RUMFS
- 19. RUMFS
- 20. RUMFS
- 21. RUMFS
- 22. RUMFS
- 23. Photos provided by RUMFS
- 24. RUMFS
- 25. RUMFS
- 26. • Otter Trawling • Gill Netting • Beach Seining • Wire Mesh “Killitraps” Chris Filosa
- 27. • Six unbaited wire mesh “killitraps” deployed in the RUMFS boat basin • Checked twice a week on Tuesdays and Fridays since 1990 Steve Luell
- 28. • Joint collaboration between RUMFS and JCNERR • Two locations sampled once a month • Graveling Point • 1st Bridge on Great Bay Blvd • 2012: August through October • 2013 – Current: May through October Steve Luell
- 29. • Seine net is 20 feet wide with 4mm mesh • Net is deployed 80 feet off the beach and towed back to shore • Three consecutive tows perpendicular to shore Steve Luell
- 30. Photos by Steve Luell
- 31. • Northern species – center of distribution is north of the Middle Atlantic Bight • Southern species – center of distribution is south of the Middle Atlantic Bight Middle Atlantic Bight
- 32. • American Eel (Anguilla rostrata) • Anchovies (Alosa spp.) • Atlantic Croaker (Micropogonias undulatus) • Atlantic Herring (Clupea harengus) • Atlantic Menhaden (Brevoortia tyrannus) • Gobies (Gobiosoma spp.) • Northern Pipefish (Syngnathus fuscus) • Sand Lances (Ammodytes spp.) • Silversides (Menidia spp.) • Summer Flounder (Paralichthys dentatus) • Windowpane Flounder (Scophthalmus aquosus) • Winter Flounder (Pseudopleuronectes americanus)
- 33. • Spawns throughout the year with a peak in the fall • Important forage for many species • Filter feeders – feed entirely on plankton • Form huge schools that can number in the hundreds of thousands • One of the most commercially important species in the Northeast Northern Species
- 34. • Important food source for many different species • Burrow into sand to escape from predators • Feed on zooplankton • Spawning occurs in winter and spring • Exact spawning locations are currently unknown Steve Luell Northern Species
- 35. • Spawn from winter into early spring • Females can produce up to 9 million eggs in a single spawning • Live along the seafloor • Prefer cold water and rocky substrate • Feed on fish and invertebrates • One of the most important commercial fisheries in the world Northern Species
- 36. • Spawn on the continental shelf from early September into late December in the Middle Atlantic Bight • Feed on crustaceans, mollusks, worms. small fish and detritus • Produce sounds using their swim bladder • Live in bays and estuaries during spring and summer • Migrate into coastal ocean in fall and winter • In recent years, juveniles have been found overwintering in NJ estuaries Southern Species
- 37. • Spawn offshore from fall to early spring • Most common between Chesapeake Bay and North Carolina • Live in shallow bays and estuaries during summer • Migrate into coastal ocean in fall and winter • Northern populations migrate south for the winter • Hampstead, NC honors the fish by holding the North Carolina Spot Festival every September Chris Filosa Southern Species
- 38. • Spawns during the spring with a possibility of a secondary spawning in the fall • Feed on mollusks, crustaceans, worms and occasionally small fish • Chin barbels are used to locate prey on the bottom • Use pharyngeal teeth in the back of their mouths to crush the shells of their prey • Produce sounds using their swim bladder • Can grow to more than 100 pounds Southern Species
- 39. • Also known as blowfish • Spawn from May to August • Male guards the eggs until they hatch Chris Filosa • Voracious predators • Feed on small invertebrates including crabs, shrimp and worms • Unlike tropical puffers, they are not poisonous Southern Species
- 40. • Highly predatory – feed on fish and crustaceans • Spawning occurs from March to September in subtropical waters • Some larvae are carried northward by the Gulf Stream • Use estuaries as nurseries - only found in NJ during summer • Juveniles die off because of cold water temperatures in fall and winter Chris Filosa Southern Species
- 41. • Voracious predators that feed on small invertebrates and fish eggs • Adults also feed on plant matter • Spawn offshore from October to March • Abundant south of Virginia • Use estuaries as nurseries - only found in NJ during summer • Juveniles die off because of cold water temperatures in fall and winter Chris Filosa Southern Species
- 42. • Highly valued commercially and recreationally • Spawn on continental shelf from September through January • Highly predatory and aggressive – they will even chase prey to the surface • Eyes on left side of body • Have large mouths with sharp teeth • Also known as fluke Amy Chianucci
- 43. • Spawn in bays and estuaries during winter and early spring • Migrate to cooler, deeper waters offshore in the summer • Eyes on right side of body • Have small mouths and no teeth • Feed on small invertebrates and plants Chris Filosa
- 44. • Found year round in estuaries • Prefers sandy or muddy bottoms • Feeds on worms, small crustaceans and insect larvae • Spawns May to October Chris Filosa
- 45. • One of the most abundant fish species in the Great Bay • May be the most abundant fish species in the western North Atlantic • Mainly feed on zooplankton • Spawn from April to November Chris Filosa • Important food source for many different species • Can tolerate a wide range of salinities
- 46. • Also known as blackfish • Spawn offshore and in estuaries from May to August • Live near structures such as rocks, pilings and wrecks • Feed on invertebrates, especially mussels, barnacles and crabs • Use pharyngeal teeth in the back of their mouths to crush the shells of their prey Chris Filosa
- 47. • Year round residents in estuaries • Tolerant of polluted waters • Spawn from April to August • Males make a loud, foghorn like sound to attract mates • Males guard the eggs until they hatch • Aggressive predators Chris Filosa
- 48. • Common from Cape Cod to Florida • Spawn offshore from late summer into winter • Most abundant in water 360 to 600 feet deep • Juveniles enter estuaries Chris Filosa • Feed on crustaceans, squid and small fish
- 49. • One of two species of “river herring” • Anadromous – live in the ocean but spawn in freshwater from April through June • Adults migrate back to the ocean after spawning • Juveniles migrate downstream to the ocean during late summer and fall • Preferred bait for the spring lobster fishery in Maine Chris Filosa
- 50. Chris Filosa • Catadromous – Live in freshwater and spawn in saltwater • Spawn in Sargasso Sea off coast of the Bahamas • Most live for about 5 years but some can live for 15 to 20 years • They can crawl across wet grass and through underground springs to get around obstructions
- 51. • Spawn early spring through summer during the full and new moon • Feed on plant material, small invertebrates and small fish • Extremely hardy • Can consume over 2000 mosquito larvae in a day • First fish in space – Skylab 3 in 1973 Chris Filosa
- 52. • Also known as bunker • Found from Nova Scotia to central Florida • Spawn during fall into early winter in Middle Atlantic Bight • Filter feeders – feed entirely on plankton • Can filter 6 to 7 gallons of water per minute • Important prey species • Commercially important
- 53. • Crab Island Fish Factory • Believed to have been founded by Joseph Wharton in the 1890’s • Menhaden were processed to make fertilizer, animal feed, paint and even margarine Steve Luell • Due to a crash in the menhaden fishery, the factory stopped operating in 1969 • The factory was officially closed in 1973
- 54. Steve Luell • Spawn along the water’s edge in May and June during the full and new moons • Eggs are an important food source for migratory shore birds such as the red knot • Feed on small clams, worms, crustaceans, and algae • Considered “living fossils” • Blue blood • Harmless
- 55. Able, K.W., M.P. Fahay. 2010. Ecology of Estuarine Fishes: Temperate Waters of the Western North Atlantic. John Hopkins Press
- 62. • Because of warming average annual temperatures: • Decrease in northern larvae entering Little Egg Inlet • Increase in southern larvae entering Little Egg Inlet
- 63. Special thanks are due to Dr. Ken Able, Roland Hagan, and the countless technicians, post-doctoral fellows, graduate students, summer interns, and volunteers at RUMFS, Melanie Reding, Kim Capone and the volunteers at JCNERR, and Chris Filosa for allowing me use his pictures.
- 64. All graphs from: Able, K.W., M.P. Fahay. 2010. Ecology of Estuarine Fishes: Temperate Waters of the Western North Atlantic. John Hopkins Press
Editor's Notes
- Pictured: Rutgers University Marine Field Station (RUMFS) Photo by Steve Luell
- Pictured: Great Bay, NJ looking toward Atlantic City
- Pictured: Cod (Gadus spp.) larvae
- The recruitment success of many marine species depends on larval fish locating inlets and entering estuaries. The responses of larval fish to climate change and human factors such as pollution can also be observed by looking at when different species enter the estuary, the size of the larval fish, and the abundance of different species.
- Sampling is conducted during the night because most larval fish prefer to travel under the cover of darkness to avoid predators.
- Sampling sites for Ultimate Bridgenetting The red dots are new sites that have been added in 2012-13. “Ultimate Bridgenetting” is when multiple sites are sampled during the same night. This is typically done every two months. The samples collected from these sites have been found to have similar species diversity and abundance.
- The rope is tied to the railing of the bridge using a bowline knot. This knot makes a sturdy loop that can support a tremendous amount of weight and can be untied easily afterward. A flow meter and a metal anchor are attached to the net and it is lowered into the water. Another flow meter is tied to the bridge using a bowline knot and lowered into the water next to the net. The flow meter measures the volume of water in each tow.
- After 30 minutes, the net is retrieved.
- The contents of the net are emptied into a bucket and will later be sorted at the field station. The numbers on the flow meters are recorded. After three 30 minute tows, the net is brought back to the field station and rinsed out into a bucket. The rinse is also sorted for larval fish.
- In addition to the flow meter (top left), temperature and salinity are also recorded. Salinity (the dissolved salt content in water) is measured using a refractometer (bottom left).
- Here is a copy of the datasheet that is filled out during this survey.
- Examples of ichthyoplankton Flatfish metamorphose video: https://www.youtube.com/watch?v=qePwW44HhNg
- Killifishes in the genus Fundulus include mummichog, banded killifish and striped killifish.
- Urophycis is a genus of phycid hakes native to the Atlantic Ocean. Some species in this genus are spotted hake and red hake.
- Sciaenidae are a family of fish known as drum or croakers. They get their name from the sounds they produce with their swim bladders. Some common sciaenids include Atlantic croaker, spot, black drum, red drum and weakfish.
- Invertebrates are also frequently caught in the plankton net. Invertebrates are animals that lack backbones.
- Pictured: Polychaete worm Like earthworms and leeches, polychaetes are annelids (segmented worms). Unlike other worms, they have distinct heads with specialized sensory organs. They are an important part of the marine food web and are preyed upon by most fish and crustaceans. Over 10,000 species of polychaetes have been identified around the world thus far.
- Pictured: Ephyra (free swimming precursor to the adult stage of a jellyfish, which is known as a “medusa”) There are several different phases in the life cycle of a jellyfish. The larvae, known as the planula, are covered with cilia which are fine hairlike organelles that are found on the surface of certain cells. The planula settle onto firm surfaces and become polyps. The polyp stage can last for many years. The polyp eventually metamorphose into an ephyra, which are able to swim. Eventually, the ephyra becomes a medusa, which is the adult stage of a jellyfish.
- Pictured: Pea Crab Pea crabs live inside oyster, clam and mussel shells where they feed on plankton and small particulates on the bivalves’ gills. Over time, they can cause damage to the gills of their hosts.
- Pictured: Crabs – Megalopa (left) and Juvenile (right) The megalopa is the post larval stage in the life cycle of a crab. It is a voracious predator that feeds on zooplankton as it rides the currents. This stage typically only lasts for a week before it molts into a juvenile crab. Juvenile crabs are able to swim and walk, and they find shelter in grasses.
- Pictured: Shrimp Shrimp are crustaceans that are closely related to crabs, lobsters and crayfish. They have flexible abdomens with fanlike tails and swim backwards by rapidly flexing these features. There are over 2000 known species of shrimp found around the world.
- Pictured: Squid There are about 300 known species of squid around the world. They have special cells, called chromatophores, that enable it to change color to match it’s surroundings. Squids swim by jet propulsion. They suck water into their mantle (body cavity) and expel it through a siphon. They can move their siphon to change direction. They release ink when threatened to evade predators.
- These are four common approaches for sampling juvenile and adult fish. An otter trawl is a cone shaped net that is towed behind a boat. With RUMFS surveys, the fish are identified to species, counted, and a subsample of 20 from each species are measured to the neared millimeter. Pictured is a deployed otter trawl. A gill net is a type of net that is suspended vertically in the water. Fish swim into it and become entangled in the mesh by the gills. Typically in RUMFS surveys, the nets are set for 60 minutes. The fish caught are identified, counted and measured. These two methods are used for sampling larger juveniles and adults.
- JCNERR – Jacques Cousteau National Estuarine Research Reserve
- Fish and predatory crabs (ex. blue crabs, spider crabs, calico crabs, green crabs) are identified and measured on site or back at RUMFS.
- The Middle Atlantic Bight is between Cape Cod, MA and Cape Hatteras, NC. A bight is a curved feature in a coast. Distribution (or range) – the geographic area where a species naturally occurs
- Over 100 genera have been caught in the ichthyoplankton survey. 95% of the entire catch has been comprised of only 12 genera.
- Because of their schooling behavior and abundance, Atlantic herring are preyed upon by many species of predatory fish, marine birds and marine mammals such as whales, dolphins and seals. Atlantic herring are found throughout the North Atlantic. They range along the North American coast from southern Greenland to North Carolina, around Iceland, and along the European coast south to the Bay of Biscay (off the western coast of France). Atlantic herring are one of the most commercially important species in the Northeast. They are typically canned and sold as sardines and kippers. They are also used as bait for lobsters and tuna.
- There are two species of sand lance found off NJ – American sand lance (Ammodytes americanus) and northern sand lance (A. dubius). American sand lances are typically found in bays and estuaries while northern sand lances live in deeper waters offshore.
- Atlantic cod are one of the top predators along the ocean bottom feeding on most fish and invertebrate species they encounter. Adult cod have few predators – sharks, seals and humans. Atlantic cod are found throughout the North Atlantic and into the Arctic Ocean. Their range extends along the North American coast from Greenland south to North Carolina, around Iceland, and along the European coast from the Barents Sea (off the northern coast of Norway and Russia) to the Bay of Biscay. Atlantic cod are one of the most important commercially harvested species in the world. Due to overfishing, the cod fishery in the northwestern Atlantic Ocean (off the Canadian Maritimes and New England) collapsed in the early 1990s and has yet to recover.
- Detritus – dead and decomposing plant and animal matter Atlantic croaker get their name from the croaking noise they produce with their swim bladder.
- Black drum get their name from the sounds they produce using their swim bladder. The sounds produced by large schools of drum can sometimes be heard and even felt through the hull of a boat.
- When threatened, Northern puffers inflate themselves to deter predators by inhaling water or air into a special chamber near the stomach.
- Summer flounder are “left eyed” flounder. They migrate inshore to bays, estuaries and the coastal ocean in the summer, and offshore to deeper water during the winter.
- Winter flounder are “right eyed” flounder. Winter flounder are highly valued commercially and recreationally.
- Hogchokers received their unusual name because farmers years ago tried to feed these fish to their hogs. The hogs had a hard time swallowing this fish because of its bony body and rough scales. Hogchokers can tolerate a wide range of salinity. They can also be found in freshwater rivers and the coastal ocean.
- Bay anchovies are preyed upon by many commercially and recreationally important species including weakfish, bluefish and striped bass. They can tolerate a wide range of salinities from freshwater to fully saline.
- The world record tautog was caught off Ocean City, NJ in January 1998. It weighed 25 lbs 0 oz.
- Oyster toadfish lie on the bottom and ambush their prey as it swims by. Feed mostly on crabs and other crustaceans, but they also prey upon small fish and bivalves. They have powerful jaws that are used to crush shells.
- The term “river herring” describes two species: blueback herring and alewives.
- American eels spawn in the Sargasso Sea off the coast of the Bahamas. The larvae drift in the ocean for 9 to 12 months before they become “glass eels”. The glass eels are carried by the Gulf Stream until they enter estuaries. Once they begin feeding, they develop pigment and become “elvers”. After several months, they grow into adults known as “yellow eels”.
- Mummichogs are important bait fish, they are preyed upon by most predators in the estuary. They are extremely hardy. Before the Clean Water Act was passed, mummichogs were the only fish species found in the severely polluted Hackensack River and Arthur Kill in New Jersey. They are used for natural mosquito control. One mummichog can consume over 2000 mosquito larvae in a single day. The mummichog became the first fish in space when several specimens were carried aboard the Skylab 3 mission for biological experiments in 1973.
- Spawning may occur year round depending on location. Limited spawning may take place in Middle Atlantic Bight coastal waters during the spring. Intense spawning takes place during the winter in the South Atlantic Bight. Menhaden are important prey for a variety of fish including bluefish, striped bass and sharks. Though they are not usually eaten by people, menhaden are a commercially important species. They are used to make fish oil, fertilizer and pet food. Menhaden are also popularly used as bait.
- The factory processed the menhaden into fish meal and oil. The fish oil was used to make paint in the United States and was exported to Germany and Canada to make margarine. About 1000 menhaden are needed to produce 20 gallons of fish oil. After the factory stopped operating in 1969, they kept a skeleton crew of eight people to maintain the grounds until 1973 in hopes that the menhaden population would rebound.
- Pictured: Horseshoe crabs spawning at Graveling Point Even though they are not fish, horseshoe crabs are a common sight in NJ estuaries. Horseshoe crabs are not true crabs. They are more closely related to arachnids (ex. spiders, scorpions, ticks) than crustaceans. At least 11 species of migratory shore birds feed primarily on horseshoe crab eggs when they stopover in the Delaware Bay. The most famous is the red knot which winters in Tierra del Fuego at the southern most point in South America and migrates north to the arctic to breed. Horseshoe crabs are considered “living fossils” because they have remained relatively unchanged for almost 350 million years. Unlike humans who have hemoglobin in their blood, horseshoe crab blood uses hemocyanin to carry oxygen. Because hemocyanin contains copper, when the blood reacts with oxygen in the air, it turns blue. Even though it looks intimidating, the spike like tail (called a telson) is not dangerous. Horseshoe crabs use the telson to flip themselves over when they get pushed upside down.
- Species that live in saltwater but migrate into freshwater to spawn are called “anadromous” fish. Examples of these are striped bass, river herring and American shad. Species that live in freshwater but migrate into saltwater to spawn are called “catadromous” fish. One well known example is the American eel, which spawns in the Sargasso Sea.
- Minimum weekly temperatures in Great Bay, NJ from 1976 to 2007. There have been fewer and shorter periods of freezing temperatures in recent years.
- Species diversity has increased throughout the duration of the survey.
- Larval data from ichthyoplankton survey (1987 – 2006) Juvenile data from killitrap survey (1991 – 2006) For a majority of southern species, less than 10 individuals have been caught.
- Larval data from ichthyoplankton survey (1987 – 2006) Solid line = Total Larvae Dotted line = Total larvae without anchovies (Anchoa spp.) Week 1 – First week of January Week 52 – Last week of December The amount of fish larvae caught is highest during the summer. The peaks in abundance from June to August are primarily the result of large collections of bay anchovies (Anchoa mitchilli) and other anchovy species. When anchovies are removed from this data, there are higher abundances of other larvae in the spring (between weeks 16 and 20, and week 24). The lowest collections of larval fish typically occur during the winter between January and March.
- CPUE = Catch Per Unit Effort Larval data from ichthyoplankton survey (1987 – 2006) Southern larval fish are frequently caught during the late summer into fall with the peak being in September. Northern species are typically caught during the winter into spring.
- CPUE = Catch Per Unit Effort Juvenile data from killitrap survey (1991 – 2006) Juveniles of northern species have been caught throughout the year in Great Bay, NJ. Southern juveniles are seen from summer into the fall but many die off because of cold water temperatures in the fall and winter.
- While a majority of the southern species that enter Little Egg Inlet do not survive the winter, several species have been found overwintering in Great Bay in recent years. If average annual temperatures continue to warm, more southern species will survive throughout the year which will completely alter fish communities in New Jersey estuaries.