A healthy shark means a healthy ocean
The phrase "a healthy shark means a healthy ocean" highlights the vital role sharks play in maintaining a balanced and thriving marine ecosystem throughout the world.
The presence and health of shark populations serve as an indicator of the overall health of the entire marine environment. Changes in shark populations can signal broader issues within the ecosystem.
Sharks are apex predators which means they are at the top of the food chain and have no natural predators. Apex predators play a vital role in maintaining healthy ecosystems by regulating the populations of their prey, preventing any single species from becoming overabundant and disrupting the food web.
In Southwest Florida, this is particularly important for maintaining healthy seagrass for grazers such as sea turtles and manatees.
Southwest Florida is home to both nearshore and offshore sharks. Many sharks, like blacktip sharks, prefer shallow, nearshore waters. Sharks like hammerheads are found both inshore and offshore near drop-offs where deeper water meets shallower areas.
Sharks can even influence the amount of carbon stored in marine ecosystems. By preying on fish that graze on seagrass and algae, they can reduce the amount of carbon released back into the atmosphere.
Seagrasses, mangroves, salt marshes, and even deep-sea sediments, absorb and store vast amounts of carbon preventing the CO2 from being released into the atmosphere and ocean. This helps regulate the Earth’s climate.
Scientists throughout the world, analyze stomach contents of sharks to determine what these sharks are eating and how that relates to their role in the food web. Examining shark stomach contents can reveal information about their overall health and the health of their environment, including potential pollutants.
Tracking tags are used to monitor shark’s movements, providing insights into their migratory patterns. Researchers use safe and ethical methods for capturing, tagging, and releasing the sharks.
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Does Lightning Affect Dolphins?
It is common for me to have to cancel charters due to lightning this time of year. Having been struck indirectly twice in my lifetime on the water in Southwest Florida, it is very personal.
Lightning can travel a surprisingly long distance both vertically and horizontally. A “bolt from the blue” can strike as far as 25 miles away from its source. Lightning has been recorded traveling hundreds of miles. Although the skies may be blue, you can still be struck and killed.
But what about dolphins? How does lightning affect them? The effect of lightning on marine wildlife is more likely to be from the powerful sound wave and pressure wave generated by a strike than from direct electrocution.
Lightning primarily dissipates across the water's surface, and fish, including dolphins, are less likely to be directly impacted due to the water's conductivity. However, dolphins, like other marine mammals, can be in the vicinity of the strike, potentially suffering from the shockwave or a glancing blow.
When lightning strikes the water, the electrical current spreads out across the surface. Water, especially saltwater, is a good conductor of electricity, so the current doesn't penetrate deeply. Dolphins spend time at the surface for breathing and socializing, making them potentially vulnerable to a strike.
Lightning generates a very loud sound and a powerful pressure wave as it dissipates through the water. These waves can cause harm to marine life, including dolphins, especially if they are close to the strike.
While some scientists estimate that whales and dolphins must have been killed by lightning in the past, there's not a lot of hard evidence. This is partly because it's difficult to determine if a death was caused by lightning or another factor.
At the first sign of thunder, it is crucial to seek shelter indoors, and stay there for at least 30 minutes after the last clap of thunder. Lightning detection equipment has confirmed bolts striking almost 50 miles away. Because I live my life on the water, I live by these codes. Safety first!
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Mangrove Recovery
As I cruise through Matlacha Pass on my back bay and sunset tours, as well as Pine Island Sound on my dolphin and nature tours, it is heartbreaking to see the damage Hurricanes Ian, Helene, and Milton have brought to our mangrove islands. It looks more like fall in my home state of the upper peninsula of Michigan than summer in Southwest Florida. My family has been in Matlacha since 1978 and I’ve never seen anything like this on the water. It seems mangroves have always thrived.
Mangroves are essential in stabilizing our local coastlines. Not to mention they are a vital home to birds and other wildlife. The vitality of our ecosystem relies heavily on healthy mangroves.
Mangroves are important to people and the ecosystem of Southwest Florida because they help reduce erosion by absorbing storm surge impacts, thus providing a natural infrastructure to protect nearby populated areas. But extreme weather events have left our mangroves in distress.
It has been over 2 years since Hurricane Ian and almost a year since Hurricane Milton. Our mangroves are showing slow signs of recovery, but full restoration is an ongoing process and is very complex.
Areas that are shallow are more likely to sprout new growth because the rainwater helps to dilute the salt water concentration. Our heavy rains in the last few weeks may cause unwanted flooding, but are beneficial to the regrowth of our mangrove forests.
In my community of Matlacha, I have witnessed the removal of dead vegetation which makes way for new growth. This is happening throughout Southwest Florida. Organizations like the Sanibel Captiva Conservation Foundation and Cape Coral Friends of Wildlife are engaged in planting mangrove trees but restoration efforts are expensive and labor intensive.
Studies show that waterflow and elevation are crucial for mangrove recovery. The impact of both Ian and Milton has been significant. Full recovery could take 10-15 years and that is if we do not get another major storm surge. Thankfully, mangroves possess a remarkable capacity to recover!
In retrospect, Hurricane Milton was the most intense Atlantic hurricane ever recorded over the Gulf of Mexico, tying with Hurricane Rita in 2005. Hurricane Ian was worse in terms of overall damage and impact. Ian was a Cat 4 when it made landfall. Milton was a Cat 3 when it made landfall.
Capt. Cathy Eagle
Capt. Cathy Eagle has spent over 40 years boating in our local waters. As a professional charter captain she specializes in dolphin and nature tours in Matlacha, Florida.
Capt. Cathy's Boat Tours
Matlacha, Florida
(239) 994-2572
www.CaptainCathy.com
