The night of 6 September, Hurricane Newton reached the Sonoran coast, somewhere just north of San Carlos. All day long, the rain came down and the wind gradually increased. By midnight the wind reached its howling peak, driving the rain sideways, knocking down utility poles and fences, uprooting trees and tearing at roofs and walls. The last privately-owned weather station peaked at over 120 km/h before it too was torn apart.
Hurricanes are a part of life here on the shore of the Sea of Cortez. Fortunately for us, most hurricanes, born far to the south, usually head out to the open Pacific and only come ashore in this general area once about every six years. Those that pass by will exert a strong influence on local weather though, and much of our summer rain is tied to the effects of not-too-distant hurricanes.
From a naturalistic point of view, hurricanes can be seen as destructive elements, or like forest fires, they can be seen as natural, periodic disturbances that re-arrange the environment, tearing out the old, and making space for new growth and new life.
Heavy rains create flash floods, washing out much of the plant life that covered the canyon floors and making room for new growth.. Much of the rain will soak into the ground, replenishing the groundwater, which will provide a long-term supply for deep-rooted trees and the vegetation of the canyon floors.
But the real changes wrought by hurricanes are found on the shore of the sea. Hurricane Newton created eight-metre-high waves that rolled up the beaches and sucked away millions of cubic metres of sand and gravel. Any turtle nests on an exposed beach would have been buried and drowned or smashed and drawn out to sea. Near-shore marine life also took a severe thrashing, uprooted and thrown ashore or dragged out into deeper water, to be fed on by a variety of marine predators and scavengers.
A walk along the shore after a hurricane reveals a glimpse into the tremendous diversity of near-shore marine life. Colourful sponges, soft corals in a variety of shapes and colours, sea cucumbers, starfish and a diverse array of molluscs lay tangled with masses of marine algae (seaweed) and unfortunate fish along the upper edge of shore.
I once found a dead bat, its huge curved claws revealing its identity as a Pacific Fishing Bat, the only species of bat known to catch marine fishes. These bats nest and roost in deep caves and crevices on islands in the Gulf. Such niches are no safe harbour when the island is being hammered by giant storm waves.
So much death is a source of food for crabs, shrimp and lobsters, as well as many other opportunistic scavengers. Gulls, terns, frigatebirds , crows and vultures also take advantage of the sudden smorgasbord laid out along the shore. Underneath the seaweed wrack are thousands of tiny crustaceans, amphipod beach-hoppers and isopod sea roaches. They have already begun to consume all of this waste and return it to the ecosystem. And along the rocky intertidal zone, new space has been made available for barnacles, oysters, scallops sponges, algae and corals.
All of this is no consolation to the people who have to deal with torn-off roofs, downed trees, and the temporary loss of such essential services as water, electricity and phone service. It only takes a couple of days without electricity to end up with a lot of spoiled food. And when your water tank runs dry, the dishes pile up, clothes and bedding go unwashed, and life gets unpleasant It makes you truly understand how dependent we are on the amenities of modern technology, and how much better they make our lives.
This is the time of year when the Olive Ridley Turtles (Lepidochelys olivacea) come ashore to lay their eggs. Here in the beaches around San Carlos they do not nest in large numbers, so there is no turtle-watching tourism, but it seems the number of nests is increasing.
The turtles hang around near the nesting sites, feeding and mating for about two months before the females come ashore to lay their eggs, so there is always a chance you will see one while snorkeling or paddling quietly around local waters.
Olive Ridleys aren’t big, as sea turtles go, about 60 cm or two feet in shell length, so watch for a head about the size of a fist, poking out of the water. When they come up for air they stick their heads above the surface several times, gulping air, before they submerge. Once they go down, they may remain submerged as long as several hours, depending on how active they are.
All sea turtle species are in danger of extinction, mostly due to human harvesting of the eggs and adult turtles. Olive Ridleys are actually the most abundant sea turtle, worldwide, but are still listed as vulnerable by the International Union for Conservation of Nature (IUCN). There is an international treaty called the Convention on Trade in Endangered Species, commonly known as CITES. Under this treaty, of which Mexico, Canada and the USA are all signatories, the trade in listed species of plants and animals, and any parts, including a shell you may find on the beach or in a market is strictly controlled. Taking a sea turtle or even a piece of a shell across the border into the U.S. or Canada will land you in very hot water, and may result in heavy fines or even jail time.
Once they reach maturity, these turtles nest annually, typically in large numbers called arribatas. Here in San Carlos, the turtles are so few in numbers that nesting occurs singly. Turtle mortality is highest in the egg stage. Nests sometimes drown in extra-high tides, can be exposed by beach erosion from storms, or be dug up by egg predators such as raccoons, coyotes or feral dogs.
The eggs hatch after about two months incubation, usually at night. The newly-hatched young dig their way to the surface, and head to the sea, guided by moonlight sparkling of the surface. They have to get into the water before first light. If they are caught out in the open, they are quickly gobbled up by vultures, frigatebirds, gulls and ravens.
Annette Felix is a local woman who is spearheading a campaign to protect these wonders of nature. She has organised support to patrol the beaches, looking for tracks or any evidence of nest-building. She has also recently put together a flyer warning people of the possibility of nests on the beach, and suggesting things they can do and should not do, in order to maximise the survival of eggs and hatchlings.
Because the eggs are just under the surface of the sand, they can be crushed by a careless pedestrian or under the wheels of an ATV or truck. Motorised vehicles are banned by law from the beaches here, but this rule is poorly enforced and often ignored. So the first rule is; be careful where you walk, and try to discourage motorists from using the beach as a racetrack.
When the hatchlings emerge, they may be misdirected by lights from homes and streets, and head away from the sea. By the time they realise their mistake, they are a long way from the sea and are vulnerable to predators. So the next rule is: lights out. Keeping exterior lighting to a minimum is crucial to the survival of hatchlings.
These animals are adapted to swim in the sea and are very good at it. But travelling overland is a tiring and difficult venture for a female turtle carrying a heavy load of eggs. Beached boats, chairs, trash and even sand castles and pits dug in the sand by happy children can be a serious impediment to females and also to the hatchlings heading for the sea. So the next rule is: keep the beach clean and free of trash and obstacles. Fill in your pits and flatten your sand castles when you are finished with them.
Following these simple rules will contribute to turtle conservation, and help to ensure that these magnificent animals which have been on the earth for millions of years, will still be here for your grandchildren to see and enjoy.
Photos from National Geographic.