The ocean is a vast, quiet place, right? Vast, yes; quiet, not so much.
As a researcher who studies coral reefs, I’ve floated above many and, when I listen closely, my ears are invariably filled with sounds. There might be the sound of small waves breaking on the beach and coral rubble rolling on the sand as the waves retreat. Beyond the sound of water, there is something quieter.
For some people, these faint noises sound like the snap, crackle and pop of breakfast cereal when milk hits it; for others, they are reminiscent of frying bacon.
Whatever the analogy, they are natural reef sounds, and noisy reefs are a very good thing. So good, in fact, that we might be able to use the sound of healthy coral reefs to improve the quickly increasing number of degraded ones.
For the past three decades, rising ocean temperatures have put the world’s coral reefs under a great deal of stress. Extreme events can kill large portions of a reef in a short time. For example, 29 per cent of Great Barrier Reef corals died during the the 2016 marine heatwave. It can take 15-25 years for a reef to recover from a bleaching event.
High-frequency sounds tend to be produced by invertebrates. Of these, snapping shrimps are the winners in terms of pitch and loudness. Snapping shrimps have one enlarged claw that, due to a marvel of anatomy and physics, makes an audible snap when closed rapidly.
The modest snapping shrimp. (Shutterstock)
If you had your ear next to the tiny crustacean, the sound could reach 190 decibels, louder than any jet plane taking off. Luckily, no one will ever be that close since these shrimps live deeply ensconced in coral crevices, snapping away day and night.
Why is sound important?
Most coral reef animals spend the early part of their lives as tiny larvae floating in the water. This larval period can last from a few days to several weeks, moving a few metres to hundreds of kilometres from where it was born.
For those long-distance dispersers, the ability to find a new home in the vastness of the ocean is critical. Three decades ago, scientists thought that larval fish were transported at the whim of currents; settling onto a new piece of real estate was largely a matter of chance.
Reef noise can also repel some fish larvae, perhaps because it reveals that there are too many predators or too few potential shoal mates. These species settle in places with sounds they dislike the least, rather than like the most.
The underwater soundscape is critical for a fish larva to know whether there is a coral reef nearby, and whether that reef is a good place to settle. But some species have better hearing than others, and the depth and structure of the habitat can also affect the way sounds emanate from the reef.
Can we use sound to repopulate degraded reefs?
It’s an obvious step to go from knowing that natural sounds are important for fish recruitment to using those same sounds to actively attract fish to depleted reefs.
A recent experiment tested this idea and found it promising. Twice as many fish, across all the major feeding groups, settled on coral-rubble reefs that played the sounds of healthy reefs than on similar but silent reefs. Healthy sounding reefs also attracted 50 per cent more species.
This suggests that acoustic enrichment could be a new and potentially powerful tool to help build up fish communities on unhealthy coral reefs. The authors warned it has to be used alongside interventions to tackle the causes of coral reef decline, climate change in particular.
Without these simultaneous actions, using an attractive soundtrack to invite small fish onto degraded reefs that offer little food or shelter would be false advertisement. And that never ends well for the fooled party.
Some Ontario doctors have started offering a free shot that can protect babies from respiratory syncytial virus while Quebec will begin its immunization program next month.
The new shot called Nirsevimab gives babies antibodies that provide passive immunity to RSV, a major cause of serious lower respiratory tract infections for infants and seniors, which can cause bronchiolitis or pneumonia.
Ontario’s ministry of health says the shot is already available at some doctor’s offices in Ontario with the province’s remaining supply set to arrive by the end of the month.
Quebec will begin administering the shots on Nov. 4 to babies born in hospitals and delivery centers.
Parents in Quebec with babies under six months or those who are older but more vulnerable to infection can also book immunization appointments online.
The injection will be available in Nunavut and Yukon this fall and winter, though administration start dates have not yet been announced.
This report by The Canadian Press was first published Oct. 21, 2024.
-With files from Nicole Ireland
Canadian Press health coverage receives support through a partnership with the Canadian Medical Association. CP is solely responsible for this content.
ISLAMABAD (AP) — Polio cases are rising ahead of a new vaccination campaign in Pakistan, where violence targeting health workers and the police protecting them has hampered years of efforts toward making the country polio-free.
Since January, health officials have confirmed 39 new polio cases in Pakistan, compared to only six last year, said Anwarul Haq of the National Emergency Operation Center for Polio Eradication.
The new nationwide drive starts Oct. 28 with the aim to vaccinate at least 32 million children. “The whole purpose of these campaigns is to achieve the target of making Pakistan a polio-free state,” he said.
Pakistan regularly launches campaigns against polio despite attacks on the workers and police assigned to the inoculation drives. Militants falsely claim the vaccination campaigns are a Western conspiracy to sterilize children.
Most of the new polio cases were reported in the southwestern Balochistan and southern Sindh province, following by Khyber Pakhtunkhwa province and eastern Punjab province.
The locations are worrying authorities since previous cases were from the restive northwest bordering Afghanistan, where the Taliban government in September suddenly stopped a door-to-door vaccination campaign.
Afghanistan and Pakistan are the two countries in which the spread of the potentially fatal, paralyzing disease has never been stopped. Authorities in Pakistan have said that the Taliban’s decision will have major repercussions beyond the Afghan border, as people from both sides frequently travel to each other’s country.
The World Health Organization has confirmed 18 polio cases in Afghanistan this year, all but two in the south of the country. That’s up from six cases in 2023. Afghanistan used a house-to-house vaccination strategy this June for the first time in five years, a tactic that helped to reach the majority of children targeted, according to WHO.
Health officials in Pakistan say they want the both sides to conduct anti-polio drives simultaneously.
WASHINGTON (AP) — Millions of people with private health insurance would be able to pick up over-the-counter methods like condoms, the “morning after” pill and birth control pills for free under a new rule the White House proposed on Monday.
Right now, health insurers must cover the cost of prescribed contraception, including prescription birth control or even condoms that doctors have issued a prescription for. But the new rule would expand that coverage, allowing millions of people on private health insurance to pick up free condoms, birth control pills, or “morning after” pills from local storefronts without a prescription.
The proposal comes days before Election Day, as Vice President Kamala Harris affixes her presidential campaign to a promise of expanding women’s health care access in the wake of the U.S. Supreme Court’s decision to undo nationwide abortion rights two years ago. Harris has sought to craft a distinct contrast from her Republican challenger, Donald Trump, who appointed some of the judges who issued that ruling.
“The proposed rule we announce today would expand access to birth control at no additional cost for millions of consumers,” Health and Human Services Secretary Xavier Becerra said in a statement. “Bottom line: women should have control over their personal health care decisions. And issuers and providers have an obligation to comply with the law.”
The emergency contraceptives that people on private insurance would be able to access without costs include levonorgestrel, a pill that needs to be taken immediately after sex to prevent pregnancy and is more commonly known by the brand name “Plan B.”
Without a doctor’s prescription, women may pay as much as $50 for a pack of the pills. And women who delay buying the medication in order to get a doctor’s prescription could jeopardize the pill’s effectiveness, since it is most likely to prevent a pregnancy within 72 hours after sex.
If implemented, the new rule would also require insurers to fully bear the cost of the once-a-day Opill, a new over-the-counter birth control pill that the U.S. Food and Drug Administration approved last year. A one-month supply of the pills costs $20.
Federal mandates for private health insurance to cover contraceptive care were first introduced with the Affordable Care Act, which required plans to pick up the cost of FDA-approved birth control that had been prescribed by a doctor as a preventative service.
The proposed rule would not impact those on Medicaid, the insurance program for the poorest Americans. States are largely left to design their own rules around Medicaid coverage for contraception, and few cover over-the-counter methods like Plan B or condoms.
