How do invasive species affect marine ecosystems?

Invasive species significantly impact marine ecosystems primarily by outcompeting native organisms, which can lead to disruptions in the food web. When non-native species are introduced to a new environment, they often lack natural predators or controls that would keep their population in check. This allows them to proliferate and dominate resources such as food, habitat, and space, which native species may rely on for survival.

As these invasive species thrive, they can displace or reduce the populations of native species, leading to decreased biodiversity. This shift can alter the dynamics of the ecosystem, as the relationships among organisms that were previously established get disrupted. For example, if an invasive predator establishes itself, it may eliminate native prey species, thus affecting the species that feed on them further up the food chain.

Thus, the key consequence of invasive species is their ability to create imbalances within marine ecosystems, making the correct answer focused on their ability to outcompete natives and disrupt food webs.