Remotely Sensed Spectral Variability Predicts Reef Fish Diversity

Abstract

In terrestrial landscapes, the spectral variability hypothesis (SVH) enables estimation of species diversity from satellite data, thereby allowing biodiversity assessments to be upscaled. Whether the SVH works in the marine realm is an open question. To answer it, we tested the ability of this hypothesis to retrieve coral reef fish biodiversity from two remote sensing platforms on a global transect of reef sites. From orbit, we trialed the multispectral and panchromatic bands of WorldView-2 (WV-2) which have a spatial resolution of 2.5 and 0.5 m, respectively. At 100 times finer resolution, we repeated the experiment using unpiloted aerial vehicle (UAV) data. Encouragingly, the SVH evidently works as well in water as has been reported on land. Spectral variability was positively correlated with fish diversity for all sensors, though the area in which the variability was computed (window size) was important. The strongest relationship between spectral variability and fish biodiversity (R = 0.48) was returned using UAV imagery corrected for surface artifacts via fluid lensing. Splitting fish into herbivores, corallivores, and piscivores revealed that different feeding strategies correlate to spectral variability at different scales. Based on our results, we contend that remote sensing data are underutilized when used to simply map benthic habitat. Spectral variation can clearly serve as a proxy for in situ reef biodiversity.

From Dialogue to Action: Ocean Foundations Gather in Stockholm

What can philanthropy accomplish when foundations working across ocean science, conservation, and sustainable development come together around a shared purpose?

That question was at the heart of the 6th UN Ocean Decade Foundations Dialogue, held September 7–9 in Stockholm, Sweden. The Khaled bin Sultan Living Oceans Foundation joined philanthropic organizations from around the world for three days of discussion, collaboration, and planning focused on accelerating progress during the second half of the UN Decade of Ocean Science for Sustainable Development.

Facilitated by UNESCO’s Intergovernmental Oceanographic Commission (IOC), the UN Ocean Decade Foundations Dialogue is a growing network of more than 30 philanthropic organizations committed to advancing ocean science, collaboration, and action. Since its creation within the framework of the Ocean Decade, the Dialogue has provided foundations with a space to exchange ideas, develop partnerships, and explore how philanthropy can help advance a healthy and resilient ocean.

Hosted by the Voice of the Ocean Foundation (VOTO), this year’s gathering began with From Depth to Action, an Opening Forum that brought nearly 100 leaders from the Swedish and international ocean community together at…

Meet IFAN: Helping Bring Navigate with Care to the Next Generation

If you’ve ever seen a lighthouse flashing from the shore or a brightly colored buoy bobbing in the water, you’ve seen Aids to Navigation at work.

Aids to Navigation, often called AtoNs, help mariners navigate safely. They can mark channels, warn of hazards, help vessels determine their position, and provide other information people need to make safe decisions on the water. Around the world, these systems help guide everything from small recreational boats to large commercial or container ships.

But safe navigation isn’t only about protecting vessels and the people aboard them. The choices mariners make can also affect the animals and ecosystems beneath and around them.

That connection between maritime safety and ocean conservation is at the heart of this year’s Science Without Borders® Challenge—and of our partnership with this year’s theme sponsor, the International Foundation for Aids to Navigation (IFAN).

Abstract

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From Dialogue to Action: Ocean Foundations Gather in Stockholm

Meet IFAN: Helping Bring Navigate with Care to the Next Generation