A stretch of coast with sand bottom and scattered rocks covered in bladder wrack is often called leopard bottom, because it resembles the pattern found in the leopard’s fur. These bottom conditions are always important to fish, since the sea trout often hunts above the sand between seaweed bushes and rocks. The contrast between the sand and the food options along the bladder wrack provides the sea trout with an advantage during the hunt.
Along with the eelgrass, bladder wrack is the most prevalent aquatic plant along the Danish shores. This seaweed attaches itself to smooth surfaces such as rocks, gravel, and other variations on the bottom. The bladder wrack is a good hiding place for food options and fish. Bottom conditions with bladder wrack are good indicators of fish being nearby.
Even though walking around on rocks along the coast may feel annoying, it’s often a good indicator of the presence of optimal bottom conditions for the sea trout and its food options. Everything from pebble to huge chunks of granite provides cover for sand hoppers, shrimp, and small fish. If there are waves, these food options are easily whirled up into the water column. A rocky bottom can be good all year round, but especially so during the cold months with few food options in the deeper water. A rocky bottom at a good depth also attracts other predatory fish such as cod and garfish.
This aquatic plant functions as a brilliant hiding place for the small food options, and simultaneously they oxidize the water around them, which provides small fish, shrimp, and sand hoppers with good living conditions. The eelgrass is also used as a resting place for the sea trout when it migrates along the coasts and particularly in late fall when the trout are headed for the river.