Ocean Circulation Edges
Dr. Mitchell Roffer of Roffer’s Ocean Fishing Forecasting Service (roffs.com) explains that offshore edges and eddies are also prime ambush spots for game fish.
“These edges are relatively strong water-density features in the ocean that are the boundaries of the water masses,” says Roffer. “These physi-cally pull and concentrate baitfish. After a few days, when there are persistent concentrations of bait, the larger fish become concentrated in these zones. The edges with the best potential are the ones with concentrations of seaweed and other floating objects like wood and trash that have baitfish associated with them. Not all edges will have a concentration of baitfish, which is usually related to the persistence, maturity and flow direction of the materials that form them.”
Like the ones in the inshore bridge- and dock-shadow scenarios, Roffer acknowledges, these edges also have different sound properties which likely influence the predator-prey relationships to the benefit of the predators. The sounds associated with these edges are likely to mask the predators’ sounds on one side, acting like a sound curtain for them to hide behind, enabling efficient ambushes.
“The best part of an eddy is where the water is pushing into the ledges, which forces the fish out of hiding in the bottom structure,” says Roffer. “When forced away from the bottom structure, the fish are more vulnerable to the larger predators, which then concentrate in these areas and start a feeding frenzy. Depending on the circulation associated with the eddy, additional good fishing action occurs in the center, where the prey and larger fish are forced closer to the surface by the upwelling and cooler water, much as with the relatively smaller western-boundary Gulf Stream eddies.”
The key is knowing how long these water-mass boundary features have been hanging over good bottom structure. This can be determined by studying sea-surface temperature charts and ocean-color satellite data, because the water masses have signature water temperatures and colors, enabling you to calculate how long a feature has been over a particular bottom structure.
As far as fishing these offshore edges goes, it’s often a matter of finding the stretch that is rich with bait and sea life. Birds are excellent indicators of a live edge and can be picked up on radar. So, when trolling or running-and-gunning down an edge, consult the radar, and also the fish finder, for any subsurface activity. Once in a bait-rich area, stick it out and work the spot thoroughly.
Sometimes locating fish is a matter of trolling tight patterns along the break or trolling up to a half-mile or so deep into the adjoining waters. Also, there are times when the fish are not at the surface along a rip or eddy and must be coaxed up. This is accomplished by trolling dredges and teasers to create more surface activity and using downriggers to place baits deep. Stopping to drop flutter jigs is also an effective method.
Edges come in many forms. Take into consideration the entire environment, create an image in your mind of what might be happening, and concentrate on where ambush zones may be. It’s a thinking angler’s game combined with some precise bait positioning. But in the end, rewards come big time in terms of game fish.
February 17, 2012
Fishing on the Edge
Strategize on fishing structure and contrast for big payoffs