By HEATHER WARD
REAL STORY — not a fish tail tale. A casual shellseeker on Atlantic Beach ignores the buffsurfers off the Fort Macon jetty and instead catches the eye of a glum surf fisherman in green waders slicing bait on top of a cooler. She interrupts his concentration (and cigarette), saving, “I have to write a magazine article on how fishermen catch fish. What can you tell me?” Without raising his head, he growls, “When you write that article, I’ll be sure and buy that magazine, ’cause I don’ know!”
Timing, it seems, matters in both conversation and fishing. And neither the fish nor the fisher were biting.
The expression “being in the right place at the right time” holds true, especially for anglers. Humans can be flexible, but fish are tied directly to water temperature. They do not consult calendars or show up alongside the beach according to our vacation schedules. Their body temperatures rise or fall with the surrounding water. Fall and spring are peak seasons for fishing because many species — bluefish. red drum, and speckled trout and bottom feeders, such as mullet, croakers, and spot — are migrating, seeking more comfortable temperatures.
Bluefish are a classic example of a seasonal migrant and a favorite of recreational anglers because of a fighting spirit. Optimum water temperature for bluefish is 68 degrees Fahrenheit (F). Anglers almost certainly will not find them in water above 84 degrees F or below 50 degrees F. Bluefish appear off the coast of Florida in late winter. By March and April, they are abundant off the coast of South Carolina, then North Carolina. New Englanders catch them in late summer. In winter, bluefish seemingly disappear, presumably headed offshore toward Gulf Stream waters.
The variety of fish that frequent North Carolina’s coast is impressive and somewhat unique. Near Cape Hatteras lies Diamond Shoals, an area of shifting sandbars where two powerful ocean currents run head-on into each other, creating a transition or convergence zone that biologists call an “ecotone.”
The cold south-moving Labrador Current meets the Gulf Stream headed north in just two places — near Newfoundland at the Grand Banks and off North Carolina’s Outer Banks — creating two of the richest fishing grounds on earth. Nutrients, plankton, bait fish and larger predatory species move along these two powerful “ocean highways.”
The best anglers intuitively understand the link between fish and their surrounding environment — and cast accordingly. Temperature and food availability are not the only influences on fish behavior and abundance. River discharge (freshwater and sediment), precipitation, and marsh and seagrass habitats also are important. Interestingly, many principles applied by surf anglers on a small beach also apply to charter and commercial fishing on larger scales in the open ocean.
Consulting local anglers is not always a dead-end strategy for finding fish. Joe Malat, longtime resident of Dare County and director of the North Carolina Aquarium at Roanoke Island, offers sage surf fishing advice.
“Knowing how to read the beach is key. Identify sections and features most likely to attract fish. Baitfish will follow shoreline contours with the larger feeding fish close behind,” Malat adds. “It also pays to be a good observer. ‘Slicks’ on the water indicate fish feeding below. And sometimes baitfish will jump when pursued by bigger fish.”
Up-to-date information is invaluable, according to Malat, and often a local tackle shop, pier, or marina is a great source for what’s biting and where. “If you use bait (rather than artificial lures), make sure it’s fresh. Replace bait that looks washed out or chewed by crabs. Fish are a lot like humans. They want to eat what looks and smells good.”
Timing tides and finding deep water matters almost as much as the season for fishing, according to Mac Currin, chair of the N.C. Marine Fisheries Commission and surf fishing instructor. Incoming or ‘flood’ tides stir up food. ‘Ebb’ or outgoing tides do the same. “High tide offers the deepest water and the most habitat for feeding fish,” Currin notes. A ‘slack tide’ — that short interval when water is almost at a standstill — is the poorest time for fishing.
“Inlets — the natural openings between two pieces of land — are bottlenecks that concentrate migrating bait. Baitfish and other food sources are swept out of the inlet as the tide falls and predators move to or from the ocean into estuary waters along this natural chum line,” Currin explains.
A slough is a deep trough running parallel to the beach, bordered by the beach and an offshore sandbar. Fish travel up and down a trough looking for food, such as crabs or sand fleas. Larger species, including North Carolina’s state saltwater fish — red drum — prefer wide, deep sloughs. Rounder and mullet frequent narrow ocean highways 15 to 20 yards offshore.
Every autumn as waters cool down, the “Frost Fishing Crew” places three L-shaped stop nets in several places along Emerald Isle. Stop nets slow schools of adult mullet migrating along the sloughs, allowing men in small boats to surround them with a seine net. Pale yellow mullet roe is marketed fresh, or smoked, and exported to Asia.
Hard structures, such as jetties, piers, bridges, or artificial reefs, provide shelter and concentrate food sources, encouraging fish to congregate. Once small marine organisms colonize a structure, larger species appear.
Anglers self-described as “pier rats” recognize that whiting, croakers, blues, mackerel or king mackerel pass by the pier, depending on the season. They also know speckled trout frequent the deep “holes” often found on the north sides of piers in the autumn.
Anglers also must appreciate the history of their stretch of beach. Food available near shore draws fish and slows their migration, but recently nourished beaches may not support the sand worms, Donax clams (coquina or bean clams), and mole crabs or sand fleas that bottom-feeding surf fishes eat. The beach may take several years to recover depending on larval availability in the area anc the distance of nourished beach.
“When Bogue Banks was nourished in winter 2001-2002 using excessively course shelly materials, sand fleas recovered within a few months, but the recovery of coquina clams was still incomplete in summer 2004,” says Sea Grant researcher Charles “Pete” Peterson of the University of North Carolina at Chapel Hill’s Institute of Marine Sciences (MS).
Water in the surf zones of beaches nourished with too much mud instead of natural sands may become repeatedly cloudy whenev waves suspend fine sediments in the water column. Spanish mackerel will come into the surf zone for food, but only if the water is clear, according to Malat.
The bottom of nourished beaches can become hard from additions of mud and shell making it difficult for small flounder to burrow or mullet to feed. Mullet do not eat fish. They swim along the bottom, sucking in sediment, extracting microscopic particles of animal and plant material.
“In MS wave tank experiments, pompano exhibited reduced feeding rates in the presence of shelly sediments, picking up shell instead of live coquina clams and sand fleas.” Peterson says. “Apparently, they were unable to distinguish the sham clam from the real deal.”
“Fishing is very similar no matter what the habitat or location,” Malat says, “from 50 feet to 50 miles from shore. Fish respond to changes in water clarity and temperatures, orient to structure, and constantly look for food.”
Recreational fishermen look for floating structures. Sargassum weed lines form at the edge of offshore currents. Sargassum provides food and an offshore nursery for small fish, crabs and bryozoans, refuge for juvenile dolphin fish (mahi mahi) and some species of grouper, and hunting grounds for bigger game fish, such as yellowfin tuna or wahoo.
Sargassum is a simple plant, a yellow or greenish-brown algae with carbon dioxide-filled bladders that keep fronds close to the ocean’s surface and the sunlight needed for photosynthesis. Huge mats are found in the Sargasso Sea — a calm area in the central Atlantic Ocean bordered by circulating currents. Storm winds and accompanying wave action often carry free-floating mats into the Gulf of Mexico, Caribbean, and onto North Carolina beaches.
When Sargassum weed gathers around a rip, sport fishermen know that their luck is about to change for the better. Rips look like rivers on the surface of the ocean ?¢‚Ç¨‚Äù long bands of calm water squeezed on either side by rough water. They occur at temperature and salinity boundaries or on top of shoals, wrecks, and underwater ledges, concentrating nutrients and plankton and attracting bigger fish.
Rips in a river or in the ocean create a kind of food conveyer belt. Striped bass will conserve energy in a pocket behind a structure, darting out into the strong current to feed as prey moves past.
Much like jetties and piers near shore, artificial reefs confound fast-moving currents, creating eddies that concentrate nutrients and food. With the help of fishing clubs and conservation groups, the N.C. Division of Marine Fisheries has placed seven artificial reefs in the estuaries and 39 in the ocean. Anglers can find artificial reefs and fish using Global Positioning System (GPS) devices. Latitude and longitude coordinates identify the location of each artificial reef. The Atlantic Beach Artificial Reef (AR-315), for example, is located roughly three and half nautical miles from the Fort Macon jetty at 34.4 degrees North and 76.4 degrees West.
SHOALS AND SATELLITES
Ecologists describe the distribution of organisms in marine ecosystems, and especially fish ecosystems, as “patchy” over both time and space. Nevertheless, people who depend on the sea for food and income need “economies of scale” to make a living. Commercial fishermen must find large aggregations of fish for the least amount of effort in fuel and equipment wear and tear. A given fishery may be large, but if it is dispersed, “catch per unit effort” is low.
So, how do fishermen find fish in so much water?
Commercial captains sometimes exploit known spawning aggregation sites, where huge numbers of fish gather to mate at the same time each year. Fish migrate hundreds of miles to these sites, using predictable routes.
Spawning grounds usually are located upcurrent from important feeding and nursery areas so that larvae can drift with the wind and currents toward ideal habitats. Weather, temperature and circulation changes can alter the timing of and locations for spawning.
The tendency of fish to school or “shoal” is the basis for most of the world’s large-scale industrial fisheries. Fish of similar size tend to cruise in the same direction together and respond to threats as one unit, making them easier to catch in large numbers — at least by fishermen. Shoaling behavior confuses some ocean-going predators, Currin says.
Before the invention of modern fish-detecting devices, practical fishermen eager to shorten their search for shoals of fish monitored bird activity. Malat reminds surfcasters: “Watch for birds — gulls, gannets or pelicans — diving into the water to pick up scraps of baitfish left over from feeding predators.”
Air spotters for commercial fishing vessels look for diving birds and marine mammals to recognize shoals and identify target species. In the Far East, fishermen trained cormorants to catch individual fish or to drive schools into fishing gear.
Porpoises and dolphins accompany shoals of yellowfin tuna, but are more visible from vessels and aircraft because of their frequent surfacing. Despite improvements in fishing gear, in some parts of the world dolphins are still caught in large purse seine nets intended to trap large adult tuna. Outer Banks tuna fishermen use 45-foot fiberglass poles, called “green sticks,” that skip lures across the ocean’s surface to catch 50- to 250-pound tuna.
Initially, military scientists copied dolphin echolocation to find submarines in all of the world’s oceans. Now fishermen use SONAR. The acronym stands for SOund Navigation and Radar.
SONAR is a type of fathometer. Fathom is a nautical measure of depth or distance of 6 feet. The word ‘fathom’ comes from the Old English, meaning outstretched arms.
Sonar equipment — essentially a speaker, microphone, stopwatch, and display — detects fish and other objects in the water by bouncing sound waves off the ocean floor and measuring the time it takes the sound to return. Newer fish finders discern ‘signature echoes’ for specific species of fish, possible because the various shapes and sizes of fish swim bladders reflect sound differently.
Rapid advances in satellite oceanography revolutionized commercial and recreational fishing by minimizing search time and operating costs. High resolution Sea Surface Temperature (SST) maps reveal weather fronts, warm or cold eddies, and the position of large currents and upwelling zones. In the same way that topographic or bathymetric maps show steep or gradual slope, tight thermal contour lines on SST maps indicate temperature breaks.
Satellite ocean color maps reveal concentrations of small microscopic plants called phytoplankton. These plants collect along the cool side of a temperature boundary where nutrients often are more plentiful. Plankton provide most of the primary production and energy for ocean ecosystems, kicking off a food chain that draws bait and predator fish.
Sara Mirabilio, North Carolina Sea Grant fisheries specialist, touts the capabilities of the North Carolina Coastal Ocean Observing System (NCCOOS) Web-based mapping tool.
“Anglers, educators and researchers can design and print their own real-time integrated ocean observation map. Available layers include, but are not limited to, bathymetry, precipitation, surface currents and temperature, wind speed and direction, artificial reefs, and coastal ports and towns. The data is more accurate because it comes from instruments on or beneath North Carolina coastal waters.”
The Oregon Inlet Fishing Center and many coastal bait anc tackle shops in North Carolina still use ocean monitoring maps and weather forecasts provided by the Coastal Ocean Observation Lab at New Jersey-based Rutgers University. The lab monitors ocean conditions by collecting information from NOAA, NASA, and Chinese satellites.
- NOAA’s Advanced Very High Resolution Radiometer (AVHRR) uses six detectors to measure heat radiation (temperature) from Earth’s surface, clouds, and bodies of water.
- NASA’s Sea Viewing Wide Field-of-view Sensor (SeaWiFS) monitors chlorophyll-a concentrations and water clarity.
- China’s FY-1C/1D system provides both ocean color and temperature data.
Throughout the last three decades, fishermen around the globe profited from improved technologies, including satellite “eyes in the sky,” sonar, radar, computerized navigation devices and fish finders, not to mention more powerful motors and better designed gear.
Our timing is not improving. Technological improvements are not keeping pace with exploitation. Scientific studies suggest serious damage from overfishing, including fundamental changes in the ecological communities of kelp forests, coral reefs, and temperate estuaries.
NOAA’s National Marine Fisheries Service reviewed 530 fish stock or stock complexes in 2006. Forty-eight stocks, some 20 percent are subject to overfishing — that is. their harvest rate is above a prescribed fishing mortality threshold.
Scientists are employing both SONAR and satellite oceanography in efforts to protect fish stocks, as well as harvest them. Supported by a North Carolina Fishery Resource Grant, North Carolina State University researchers Jeff Buckel and Paul Rudershausen, along with commercial fishers Alex Ng and Tom Burgess, are using SONAR with hook-and-line sampling to survey reef fish over the proposed Snowy Wreck Marine Protected Area (MPA).
Their data will provide a snapshot of fish distribution, abundance, and size prior to closure of the area and ultimately will help determine the MPA’s effectiveness. “Most of the reef fish are located on a narrow area of high relief on the outer edge of the continental shelf,” Buckel says.
“This shelf break comprises roughly 20 percent of the MPA area and lies some 60 to 120 meters below the ocean’s surface. The top five species collected are red porgy, snowy grouper, scamp, speckled hind, and knobbed porgy,” Rudershausen adds.
Analyzing trends from satellite imagery can help identify large-scale habitat changes that affect larval recruitment, migration, and ultimately overall numbers of a particular species, says Barton College geographer, L. Jean Palmer-Moloney.
“For now though, remote sensing technologies remain expensive and imperfect tools in fishery conservation and management efforts,” she says. “Biologists often need tight spatial resolutions, sometimes down to one-meter plots. Moreover, data must be gathered with a frequency that makes sense. This is all about scale and time frames. To better understand moving fish in real time, we must find the money to improve sensors, collect data more often, and analyze it faster.”
This article was published in the Winter 2008 issue of Coastwatch.
For contact information and reprint requests, visit ncseagrant.ncsu.edu/coastwatch/contact/.