Body size of 85,000 marine species mapped in new database

Researchers have launched a database that tracks the maximum body size of over 85,000 marine animal species. This resource spans creatures from tiny zooplankton to massive whales.

“Put simply, biologists have tended to focus on bigger organisms. And as a result, a lot of our understanding of how marine food webs and ecosystems work is based on knowledge of these larger species,” said study co-author Dr. Tom Webb from the University of Sheffield.

For decades, marine science has placed the most emphasis on large species. Now, smaller species are getting some attention. Including them matters because they make up most of marine biodiversity and play vital ecosystem roles.

Why size matters in marine species

Body size shapes how ocean creatures live and interact. It influences where they feed, how they move, and their chances of surviving environmental changes.

Research confirms that size patterns help predict the ecological impact of marine species. Studies show ecosystems are organized by size, with bigger animals eating smaller ones.

Missing size data has hindered climate and conservation models. With 40% of marine species now included, scientists can make stronger predictions. They expect coverage to rise to 75% in the next two years.

The project is led by Dr. Craig R. McClain at the University of Louisiana, working with experts from Sheffield, Tufts, Stanford, Hawaiʻi, and Virginia Tech.

“Body size isn’t just a number – it’s a key to how life works,” said Professor McClain. “This database fills a critical information gap and offers a fresh perspective on ocean biodiversity.”

How tech helped gather size data

The creation of MOBS relied on automated data mining tools that pulled species measurements from thousands of publications and records.

Advances in machine learning helped standardize inconsistent formats and reduce manual entry time.

The researchers also used global taxonomy systems like WoRMS to verify species names and classifications. This integration ensured that their data could be reliably linked with other major marine datasets.

A massive marine dataset

Known as MOBS (Marine Organismal Body Size Database), it records maximum measures like length, width, and height – standardized across 30 marine animal phyla. The initial release includes 85,204 species and over 181,000 size entries.

The data draws from scientific literature, museum records, and online repositories. It’s open source and freely available through GitHub.

With size data spanning tens of thousands of species, scientists can now explore how body size evolved across different lineages.

They can test long-standing theories about how environmental pressures, such as ocean depth or temperature, shaped the evolution of size in marine animals.

The database also enables comparisons between extinct and living species. By integrating fossil records, researchers can trace size shifts over time and investigate extinction patterns related to body size across evolutionary history.

Smaller species, bigger blind spots

Scientists are already using MOBS to explore biases in species documentation. Smaller marine species often get overlooked in biodiversity surveys, raising questions about conservation priorities.

Researchers are also analyzing how body size changes with climate shifts. Since size affects metabolism and vulnerability, this insight is critical for forecasting ecosystem responses.

This database has real-world implications. Fishing large species disrupts food webs, and those effects ripple down to smaller prey.

Now models can account for these interactions accurately. Insights from birds show larger species face higher extinction risk. A robust marine size dataset may reveal similar trends, improving risk assessment and policy interventions.

Protecting small, vulnerable species

Policymakers and fisheries managers can use size data from MOBS to better regulate marine harvests. Knowing the size structure of species helps design catch limits that maintain ecological balance and prevent overexploitation.

The database also supports marine spatial planning. Regions with high concentrations of small or vulnerable species can be prioritized for conservation zones, improving how resources are allocated for ocean protection.

The project aims to integrate with OBIS (Ocean Biodiversity Information System) and other marine data platforms, enabling spatial and ecological mapping.

With open-source access, the database invites global contributions. Scientists worldwide can suggest updates, correct errors, and share measurements, promoting a community-based science model.

Marine education and citizen science

The open-access nature of the MOBS database also opens doors for educators and citizen scientists. Teachers can use real species data in classrooms to introduce students to marine biology, ecology, and data science.

Citizen science groups can incorporate the database into biodiversity monitoring projects. Having access to maximum body size info helps with field identification, ecosystem modeling, and community-led marine conservation initiatives.

Ocean ecosystems face mounting stress. Climate change, overfishing, and habitat damage threaten marine life.

This dataset gives conservationists better tools to understand and protect ocean biodiversity. By grounding strategies in data that span tiny plankton to whales, MOBS bridges ecological gaps and supports stronger conservation efforts.

The study is published in the journal Global Ecology and Biogeography.

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