Dynamic Environmental Niches of Marine Invasive Species Over 200 Years

Area of Science:

• Ecology
• Conservation Biology
• Invasive Species Research

Background:

• Predicting species invasions is vital for conservation efforts.
• A key assumption is niche stability: environmental conditions in native habitats predict introduced ranges.
• This study investigates niche conservatism and expansion in marine invasive species over time.

Purpose of the Study:

• To quantify changes in occupied environmental niche space for marine invaders globally.
• To assess the degree of niche overlap between native and introduced ranges over 200 years.
• To evaluate the predictive power of native environmental drivers for introduced species distributions.

Main Methods:

• Global-scale analysis of 778 marine invaders using 200 years of invasion records.
• Quantification of niche space overlap between native and introduced ranges.
• Assessment of niche filling and expansion over time.

Main Results:

• The majority of native environmental niche space remained unfilled by introduced marine species, even after two centuries.
• Niche overlap between native and introduced ranges increased with time since invasion but remained low on average (never exceeding 20%).
• These findings indicate limited niche conservatism and expansion in marine invaders.

Conclusions:

• Native environmental drivers are unlikely to accurately predict introduced marine species ranges within decadal time frames.
• Conservation strategies should not solely rely on native niche characteristics for predicting invasion risks.
• Further research is needed to understand the factors limiting niche filling and to improve invasion predictions.