Striped bass, also known as stripers or rockfish, are highly sought-after fish found along the Atlantic coast of North America and in various inland waters. These adaptable fish are opportunistic predators, consuming a wide variety of available food sources. Their diet is diverse, reflecting their ability to thrive in different habitats and adapt to changing conditions.
Primary Prey
Striped bass are voracious eaters, with their diet primarily consisting of other fish and a significant amount of invertebrates. Studies on their stomach contents reveal a broad spectrum of prey items, often exceeding 65 fish species and over 45 invertebrate species.
Forage Fish
Forage fish constitute a major portion of an adult striped bass’s diet. Atlantic menhaden, often called bunker, are a staple, especially in areas like the Chesapeake Bay, where they can account for over 45% of the diet. Other commonly consumed fish include various species of herring (alewives, blueback herring, sea herring), anchovies (bay anchovies), sand eels (sand lance), silversides, mummichogs, and eels. Smaller fish like juvenile weakfish, spot, and Atlantic croaker also become important prey depending on local abundance. Striped bass often corral schools of baitfish, driving them to the surface for easier capture.
Crustaceans
Crustaceans are an important food source for striped bass, particularly in estuarine and coastal habitats. Common examples include green crabs, lady crabs, blue crabs, shrimp (grass shrimp, sand shrimp, mysid shrimp), and juvenile lobsters. Smaller striped bass frequently consume crustaceans as a significant part of their diet.
Mollusks and Worms
Mollusks and marine worms also contribute to the diet of striped bass. Squid are a notable prey item, especially in certain coastal areas like Cape Cod, where striped bass actively hunt them. Mussels and various marine worms are also consumed, particularly by smaller striped bass. Striped bass forage along the seabed, eating creatures like clams and worms.
Other Invertebrates
Beyond fish, crustaceans, mollusks, and worms, striped bass consume other invertebrates. This can include insect larvae, particularly for younger fish, and other larval forms of marine life. They will attempt to consume almost anything that fits into their mouths and is available.
Dietary Shifts Through Life Stages
A striped bass’s diet changes significantly as it grows, adapting to its increasing size and energy demands. This progression reflects a move towards larger, more energy-rich prey.
Larval Stage
Newly hatched larval striped bass are tiny, beginning their feeding journey with microscopic organisms. Their diet primarily consists of zooplankton, small aquatic animals crucial for their early development and rapid growth.
Juvenile Stage
As striped bass transition into the juvenile stage, their diet expands to include larger invertebrates and very small fish. They consume insect larvae, small crustaceans like amphipods, isopods, and mysid shrimp, and other larval fish. Juvenile striped bass also consume small mollusks and marine worms.
Adult Stage
Adult striped bass become primarily piscivorous, meaning their diet is dominated by other fish. They target larger forage fish such as menhaden, herring, and mackerel, which provide the high protein content needed to support their substantial size and energy requirements. While fish are their primary food source, adult striped bass continue to consume invertebrates like crabs, squid, and worms when abundant.
Environmental and Seasonal Influences
The diet of striped bass is not static; it is heavily influenced by their environment and the changing seasons. Prey availability, habitat characteristics, and water temperature all play a role in shaping their feeding habits.
Habitat Differences
Striped bass inhabit a wide range of environments, from freshwater rivers to open ocean, and their diet varies accordingly. In freshwater environments, such as inland lakes and reservoirs, they primarily feed on species like shad, panfish, and crayfish. Estuarine habitats see them consuming crabs, worms, and small fish like bay anchovies and menhaden. In the open ocean, larger pelagic fish, such as mackerel, become more significant prey items.
Seasonal Availability
Prey availability fluctuates throughout the year, directly impacting the striped bass diet. During warmer months, when their metabolism is higher, striped bass are more active and feed more frequently on abundant baitfish. In colder months, their metabolism slows, reducing their appetite, and they may rely on overwintering species or less active prey. For instance, certain herring species are abundant in New England coastal waters during late spring and early summer, becoming a primary food source for migrating stripers.
Water Temperature and Salinity
Water temperature significantly influences striped bass activity and feeding behavior. They generally prefer water temperatures between 55°F and 68°F (12.8°C to 20°C), where they are most active and feed aggressively. When water temperatures rise above 70°F (21°C), they can become stressed, seeking cooler, deeper waters, and their feeding may decrease. Conversely, in colder water below 50°F (10°C), their metabolism slows, reducing their feeding frequency.
Relevance for Anglers and Ecosystem Health
Understanding the diet of striped bass provides practical insights for anglers and highlights their broader ecological significance. This knowledge can improve fishing success and underscore the importance of maintaining healthy aquatic environments.
Angler Implications
Knowing what striped bass eat helps anglers select appropriate lures, baits, and fishing locations. For instance, when striped bass are actively feeding on menhaden, anglers often use live menhaden or lures that mimic their appearance and swimming action. If striped bass are targeting sand eels, slender plastic lures that imitate these baitfish can be effective. Understanding seasonal and daily feeding patterns, such as peak activity at dawn and dusk, also guides fishing times.
Ecosystem Role
Striped bass serve as important predators within their ecosystems, influencing the populations of their prey species. Their role helps maintain balance in coastal food webs. A healthy forage base, particularly abundant populations of baitfish like menhaden, is important for sustaining robust striped bass populations. Conservation efforts often focus on managing these forage fish to ensure enough food is available for predators like striped bass and other species.