Understanding the marine biology of predator and prey can pay big angling dividends.
Ecology is the branch of biology that deals with organisms’ relationships to each other and their environment. Ecological interactions can occur between individuals of the same species or across different species, and are categorized into various types; examples are predation (including parasitism), competition, mutualism (where both organisms benefit), and commensalism (where one organism benefits while the other is unaffected).
Experienced anglers may not realize it, but they exploit these ecological interactions to enhance catch sizes and success percentages. Once new anglers incorporate a few of these key scientific concepts into their own understanding, it will accelerate their angling productivity too.
Stay In School
Baitfish species shoal and school up for a variety of reasons, including having more eyes on the lookout to detect threats. Such interactions can even occur across species. But why else exactly do schools of baitfish tightly ball-up when predators are lurking? Well why do introverts (like this author) counterintuitively prefer larger social gatherings over smaller ones? Obviously, there is safety in numbers. Being around more people, than less, decreases the chances of any one person being targeted by others for interaction, thereby diluting the social pressure to engage in any long conversation.
Another simple analogy would be to imagine yourself back in school when random students are being selected to give oral presentations, but you have nothing prepared to present. You sweat nervously out of fear your name will be called next! In such an instance, wouldn’t you feel safer if the class had more students in it? This is because the likelihood of the teacher calling on you to talk is far lower in a larger class. Similarly, an individual baitfish has less chance of getting targeted and eaten when in a big group as compared to a small group or especially when alone. The benefits to this ecological interaction extend beyond the probability of getting singled out, however.
A large, closely packed cluster of bait can resemble a singular object from afar. Non-anglers can often mistake bait pods as such, and start wailing “shark,” “monster,” “what the blank is that?” At times, especially from a distance, predators can likely be tricked too. Instead of recognizing their lunch for what it is, predators may scram in fears of becoming just that.
Predator disorientation is another benefit of schooling as numbers in motion can confuse even the sharpest predatory eye. You can test this on yourself with birds; try following an individual pigeon or sparrow in a flock of hundreds or thousands. You’ll soon see it’s near impossible, especially when the flock is making erratic turns. The mass movement of prey in a bait ball can confound the targeting systems of the predators; unfortunately for the prey, evolution is an arms race where the predators have developed their own mechanisms to compensate for such defenses.
For example: sailfish and tuna have developed superior speed. All billfish use their signature front blade to more accurately target and indiscriminately slash at prey, while sailfish use their sail for corralling. The long tail of a thresher shark requires minimal accuracy as it whip-stuns baitfish from a pod, whereas a fluke’s camouflage allows it near enough proximity to where singling out an individual baitfish is no longer an obstacle. Count on the bluefish’s energy and aggression to give it the persistence to push past any failed strike, but it’s the enhanced lateral line in the striped bass that helps that species key in on the slowest and/or most vulnerable of the baitfish in a ball. A personal favorite is the spinner shark’s erratic twisting while speeding through piles of bait.
Weirdest benefit of all, it is easier for a baitfish to swim and turn when tightly schooled than when otherwise. An individual bait can take advantage of nearby water vortices created by adjacent fish, which reduces the energy costs of movement. All of this precise, coordinated movement is a science in and of itself, and is mediated through the lateral lines of the bait fish. These sensory organs detect the surrounding flow and water pressure changes that cue the bait fish to properly respond with the school. This anti-social-distancing tactic for prey is very effective and frequently utilized against predation.
Working Birds
Dispersed or balled-up into a pod, baitfish in the upper water column cannot escape onslaughts from above. One of the first ecological interactions learned by new saltwater anglers is the importance of marine birds diving at the water. A single bird doing it once may simple mean its picking up some floating organic debris; however, when repeated, especially with multiple birds, hints towards the presence of numerous bait fish. Prey lingering in the danger zone of the upper water column implies something more; predators from below are pressuring the bait to the surface. This is often the case where predatory fish, birds, and even marine mammals are unconsciously cooperating to corral the prey. Knowing and seeing this alerts anglers to where they should cast.
Experienced anglers can gain a more precise account of a bird frenzy by recognizing nuances. The action on the water’s surface and the speed at which the frenzy is moving suggest the prey being one species versus another. A greater tell is the makeup of the aerial army. The presence of seagulls and/or smaller marine birds eliminates possibility of bass alone pressuring adult bunker. Adult menhaden tend to be too large and strong for ordinary seagulls to subdue, unless of course accompanying bluefish shred them into more manageable portions. So when seagulls and smaller marine birds are present, it may be suggestive of smaller bait (i.e. peanut bunker, mullet, sand eels, bay anchovies).
Witnessing an osprey or cormorant dive-bomb, though, may suggest adult bunker. Raptor and raptor-like sea birds have no difficulty in grabbing, lifting, and ingesting whole adult menhaden. And with their superior velocity, they can extract them from hidden depths. With this knowledge, an angler can locate feeding fish and adjust any pre-planned fishing strategy accordingly.
This information should not be exploited against other anglers with what’s called a ‘popcorn blitz,’ Throwing a bunch of buoyant human food into the water will attract birds, and entice anglers to abandon their pre-posted positions. Both surf anglers and boaters have often resorted to this trick to divert crowds away from cuts, points, rips, wrecks, reefs, and other productive zones. Albeit amusing and spot-liberating, this dirty trick is not healthy for our marine birds.
Where’s The Bass?
Given enough size difference between individuals, bass and blues at times prey on each other. Such is common across the animal kingdom, where a juvenile of a predatory species can be the prey until certain sizes are reached. Bass and bluefish cooperate though too. Actually, nothing for the bluefish is gained or lost through the transaction, but the striped bass makes out like a bandit.
Stripers are more strategically opportunistic and energetically conservative than bluefish. When clusters of both simultaneously cross paths with a bait pod, bluefish go on their expected eating rampage. However, bass will often lay low and back in these mixed predation events. They allow the sharp teeth of the blues to obliterate the baitfish into shreds. Pieces of the dead and wounded stragglers drift beneath the school where the stripers linger ready to inhale them. This situation can be similarly exploited by fluke and weakfish as well!
An angler with this knowledge and the intentions of catching something other than a bluefish can adjust their strategy to get low in the water column. This can be done by throwing a rapidly descending offering (weighted bait, jig, shad) or by casting behind or beyond the feeding frenzy so that there’s sufficient time for the offering to sink.
The concept above applies to stripers across age/size groups too. The more energetic and water temperature-tolerant younger bass will likely join the upper levels of a blitz sooner than an older cow. Unless an ideal narrow range of conditions are in place – primarily water temperature – bass from 40 pounds to super-size will hang low and back optimizing their energy expenditure. Trophy fisherman not only know this, but they have a self-restraint (or possibly a jadedness) to forgo catching a ton of smaller fish for the opportunity at a monster. The differences in behavior across age extend well beyond this, but that is a separate article.
What’s All The Fuss?
Anglers are, in a sense, marine organisms engaged in these same ecological interactions as the fish. This is why fishermen instinctually check out other gatherings of anglers. Young people may think FOMO (Fear of Missing Out) is partly to blame, however, that only follows and exacerbates the rush to the crowd. The initial curiosity is seeded by our cognitive power for pattern recognition, memory, and problem solving. We are smart enough to ask ourselves, “why is that giant fleet clustered in a small area as opposed to anywhere else?” Then the curiosity deepens!
FOMO can pull even the firmest anglers with predetermined plans off course, if only just for a peak. Often times these clusters of anglers will indeed be gathered on a higher number of fish compared to the surroundings. In this way, anglers themselves are unconsciously alerting others to the presence of the fish. Conscious cooperation here can extend into anglers using boats or casts to corral the baitfish.
| TIP OF THE ICEBERG |
| There are countless examples of ecological interactions that a Northeast saltwater angler can exploit. When fishing, be vigilant on the water. More patterns of how species interact will reveal themselves. Understanding the interactions of organisms with their environment, within a species and across species, can help you become a more productive angler. Understanding the behaviors of other anglers can help toward that same end, as well as toward being a better sportsman and more content fisherman.
– Aguiar |
The cooperative nature of these scenarios are quickly overtaken by a sense of competition, and opportunity to catch rapidly degenerates. For example, a boat overzealous to get on the fish does just that, literally. We’ve all seen the captain who drives their boat on top of the bait pod, dispersing the bite and ruining it for everyone! Once the ratio of anglers to the estimated quantity of fish gets too high, any cooperation transitions into competition anyway.
So it can be worth investigating the scenarios where other anglers are clustered, but only briefly and more so for contextual information. If one arrives to the cluster early, or there is an excess of fish and room, then fish away! However, the dedicated angler should always have a preplanned strategy, avoiding the use of these situations as a crutch. It would be foolish to bypass a good bite, but relying on crowds to locate it first is the definition of a bent-rod-watcher.
This is where the concepts of marine ecological interactions overlap with proper angling etiquette.
The author is Associate Professor of Biology at Stockton University in New Jersey, and has a Ph.D. in Molecular Biology and Genetics. He’s also a hardcore surfcaster who spends much of his time away from class in the field chasing striped bass from the Chesapeake to New England and all points in between.
