How deep is the ocean? – the Conversation

Mother humpback and calf (courtesy of NOAA Photo Library CC BY 2.0 via Flickr).

Explorers started making navigation charts showing how wide the ocean was more than 500 years ago. But it’s much harder to calculate how deep it is.

If you wanted to measure the depth of a pool or lake, you could tie a weight to a string, lower it to the bottom, then pull it up and measure the wet part of the string. In the ocean you would need a rope thousands of feet long.

In 1872 the HMS Challenger, a British Navy ship, set sail to learn about the ocean, including its depth. It carried 181 miles (291 kilometers) of rope…

The “Octopus Garden” – MBARI

Pearl octopus (Muusoctopus robustus) nesting in rocky crevices in the "Octopus Garden" on the Davidson Seamount, part of the Monterey Bay Marine Sanctuary off the central coast of California. (courtesy of Ocean Exploration Trust / NOAA, public domain).

Deep below the ocean’s surface just off the Central California coast, thousands of octopus gather near an extinct underwater volcano. The Octopus Garden is the largest known aggregation of octopus anywhere in the world…

Where does beach sand come from? – the Conversation

Pebbles on the Beach (by Susanne Nilsson CC BY-SA 2.0 via Flickr).

Question from Sly M., age 6, Cambridge, Massachusetts…
There’s more to beach sand than meets the eye. It has stories to tell about the land, and an epic journey to the sea. That’s because mountains end their lives as sand on beaches….

Twelve New Kids’ Beach Reads to Inspire Action and Adventure – Hakai Institute

Illustration from Dear Polar Bear by Gabrielle Prendergast, Illustrations by Marcus Cutler, courtesy of Orca Book Publishers.

Young readers can become archaeologists, seaweed harvesters, and Arctic explorers, all through the pages of books.

One of the best antidotes to climate anxiety is climate action, and there are plenty of places to look for inspiration—including within the pages of several of this season’s new kids’ beach reads. If the tournament’s a go, I’ll be bringing them with me for the ride…

Mangroves: “Superhero” Ecosystems – Frontiers for Young Minds

Positive interactions in mangrove ecosystems: (1) Multi-species plantations can sequester more carbon in sediments and can increase root yields. (2) Microbial communities receive food from mangrove root (3) Mixed stands of mangroves can provide association defense against herbivory. (4) Mangrove roots allow for oyster recruitment and reduce sedimentation stress (5) Mangroves provide carbon to sponges and sponges provide nitrogen to mangroves (6) Mangrove roots provide habitat for sponges and tunicates (7) mangrove pneumatophores trap algae and oysters, which support diverse mollusk communities. (8) Mangrove plantations sequester carbon in sediments (9) Other plant species can increase recruitment of mangroves (10) Higher densities of mangroves allow for more resilience to sea level rise. (11) Nearby coral reefs protect mangroves ((by Julianna J. Renzi, Qiang He and Brian R. Silliman, CC BY-SA 4.0 via Wikimedia).

Because mangroves live along the land-ocean boundary, they are unique plants that provide several benefits to nature and humans. For example, mangroves provide refuge and food for organisms, hurricane protection, and water filtration; mangroves also promote the release of oxygen into the atmosphere and the uptake and trapping of carbon dioxide, which helps to fight against climate change. To understand mangrove ecosystems, it is important to consider the role of the microorganisms that live there…