California’s Squid Run

As you drop into water as black as night, thousands of pulsating squid in search of mates suddenly surround you. Mating activity is everywhere as multiple males attack single females. The excited squids’ chromatophores (pigment cells) flash colors reminiscent of a Las Vegas neon sign and put you in the middle of a living, moving light show. The action is so frenetic that animals are in your gear and bounce off every inch of your body.

Male squid wrap their tentacles around females during a night dive at Catalina Island.

Looking Into the Lungs

During medical school Peter Lindholm joined a laboratory researching aviation, space and underwater physiology, where he developed a passion for breath-hold dive physiology, about which he wrote his doctoral thesis. As one of the physicians for the Swedish Sports Diving Federation (SSDF), he was involved in developing breath-hold dive protocols and training the first instructors of competitive breath-hold diving. After clinical training as a radiologist, Lindholm moved to San Diego, California, where he leads a research group focused on dive physiology and dive medicine.

Lindholm conducts a breath-hold experiment with standardized lung volumes and invasive measurements of cardiac output and arterial blood gases.

Diving in a Time Capsule

Thunder Bay National Marine Sanctuary in Lake Huron off the northeastern coast of Michigan has nearly 100 known shipwrecks, and others are still being discovered. The oldest shipwreck there sank in 1849, but many wrecks are from the mid- and late 1800s to the early 1900s. The location, history and variety of ships — from wooden schooners to freighters — make Thunder Bay special. The wrecks are at various depths, ranging from the snorkel zone to recreational and technical diving levels.

A closed-circuit rebreather diver checks out the yawl boat off the stern of the Cornelia B. Windiate.

Safety Tips for Dive Operators and Professionals

The first step in ensuring the safety of staff, divers and the public is to develop a detailed awareness of the real risks present in all operations performed by dive businesses and professionals. DAN® has produced a brief guide for anyone responsible for safety. The guide offers an introduction to identifying and understanding 17 of the most common areas of concern. These potential incident sources highlight the kinds of considerations that need attention and help operators to better understand how they might apply this knowledge to their businesses.

Managing risk is an essential part of improving safety in the dive industry.

The Case of Catastrophic Kelp Loss

For more than five years, divers and scientists along the U.S. West Coast have watched a disaster play out before their eyes. Sunflower sea stars fell victim to a wasting disease, which wiped out roughly 90 percent of the global population in 2013. Seven years later, scientists see no signs of recovery. Without the sea stars, the population of purple urchins that sea stars eat has exploded and mowed down entire forests of bull kelp. The West Coast experienced intense ocean warming from 2014 to 2017, and by 2015 divers began seeing urchin barrens — vast swaths covered in piles of spiny creatures and little else.

Purple sea urchins attach to feed on giant kelp.

Shallow-Water Arterial Gas Embolisms

Pulmonary barotrauma can occur in a shallow swimming pool if a diver holds their breath during ascent or inadvertently floats to the surface while holding their breath. Most dive-related pulmonary barotraumas occur in compressed-gas diving due to pulmonary overinflation during a breath-hold ascent. Pulmonary barotrauma can occur even with normal breathing if there is an obstruction in the bronchial tree that prevents one lung segment’s normal ventilation.

Even in shallow water and while preoccupied with other tasks, it is important to breathe continuously. Relax and breathe normally during ascent to help avoid pulmonary barotrauma.

Forging a Blue Economy

For the founders of three of Indonesia’s dive resorts, the mission was clear: Protect the region’s natural resources by providing economic, educational and environmental benefits while empowering residents to participate in the process. These visionaries blazed a path for a “blue economy” — ensuring sustainable use of ocean resources while promoting economic growth and improved livelihoods for the people who live there.

A group of blacktip reef sharks circles over a shallow coral garden in the Misool Marine Reserve in Raja Ampat, West Papua, Indonesia.

Surviving Triple Dangers in the Maldives

A diver didn’t heed the divemaster’s warning and was lost at sea. Deploying his large surface marker buoy helped with his rescue. DAN recommends that divers always listen to the dive briefing and follow all directions and always carry an SMB and reel. If your breathing-gas supply is critically low, get to the surface at a safe ascent rate, and then monitor for signs of decompression illness. It is better to deal with DCI on the surface than to run out of breathing gas at depth.

Having the appropriate safety gear with you on every dive and knowing how to use it are integral parts of being prepared, as are remembering your training and following the dive briefing instructions.

It Takes a Village

Ocean literacy is important for the public to make informed decisions about ocean restoration efforts and to take increased individual responsibility in those efforts. Younger generations are crucial for developing an ocean literate society, but adequate ocean science education is a challenge for underserved and underfunded schools. Informal educational opportunities run by the Black Girls Dive Foundation (BGDF) fill the knowledge gap and are a resource for environmentally minded students.

BGDF scholars clean coral at the coral nursery with the Coral Restoration Foundation.

Oceanic Unveils Predator Freedive Equipment

This Summer, dive and snorkelling gear manufacturer Oceanic is inviting its customers to “Set Their Dive Free.” Dubbed the Predator line, the company is releasing a free dive-specific fin, mask, snorkel and mesh carry bag to support this growing segment within the watersport market.

sponsored post - Oceanic World Predator Line of Freedive Equipment