Manatees, research and conservation

This October 2018 video says about itself:

There are three species of manatee in the world and they can be found in coastal rivers and waters.

From the Smithsonian Tropical Research Institute in Panama:

Underwater manatee chatter may aid in their conservation

September 30, 2019

Summary: Scientists propose a new method for calculating populations of the Antillean manatee, a marine mammal in danger of extinction, through underwater recordings.

Listening in on manatee conversations could help restore populations of this endangered marine mammal. Each manatee has its own voice: their calls can be traced back to specific individuals, offering a way to estimate how many of them are present in a particular habitat in a given time. Researchers from the Smithsonian Tropical Research Institute (STRI) and the Universidad Tecnologica de Panama, (UTP) propose a new method for detecting these calls from underwater recordings.

Antillean manatee (Trichechus manatus manatus) populations have been continuously decreasing for a decade and are predicted to drop an additional 20% within the next two generations, according to International Union for Conservation of Nature (IUCN) criteria. There are a few reasons for this, most of which are due to human pressure, including illegal hunting, habitat degradation, boat collisions and pollution.

In order to counter this decrease, conservationists need to be able to estimate manatee numbers and understand how they use their habitat. In Panama’s Bocas del Toro province, however, manatees live in turbid brackish waters, covered by aquatic vegetation, so standard visual counting methods are less than ideal.

“Estimating the manatee population in Panama is like working in total darkness: you cannot count what you cannot see,” STRI marine ecologist, Hector M. Guzman, said. “We made a first attempt few years ago using a side-scan sonar within the protected wetland, which yielded good preliminary results. However, the method was not suitable for other non-navigational rivers with dense aquatic vegetation.”

Although hard to sight, manatees often communicate with one another underwater, emitting whistles, squeaks and chirps to attract mates, warn their neighbors of danger or stay in touch with their offspring. With this in mind, researchers turned to sound.

“Working with a marvelous team of signal-processing specialists from the UTP, we created a new research horizon for manatees, opening the field for a continuous monitoring system of the populations based on vocalizations,” Guzman said. “Now, we can identify where, when and who is there, which we ecologists need to model population size and changes in time and space.”

The proposed new method for counting manatees, based on their vocalization spectrograms, was tested on a large data set of underwater recordings from the Changuinola and San San rivers in Bocas del Toro. This scheme uses the uniqueness of manatee sounds to generate individual clusters, with each cluster corresponding to a single manatee.

“This approach required the collaboration of several different specialists, and almost two years of development and analysis, to process over 375,800 two-minute audio clips from three years of continuous monitoring, to be able to successfully count and identify individual manatees from Bocas del Toro protected wetlands,” said Fernando Merchan, signal-processing specialist from UTP and lead author of the publication.

The scientists found that this method offers similar estimates of manatee counts than those encountered in previous studies, through different approaches. By linking individual vocalizations to specific manatees, this underwater acoustic-monitoring technique may become a valuable tool for ecologists to infer the seasonal presence of manatees in certain sites.

With the support of the National Secretariat for Science, Technology and Innovation of Panama (SENACYT), this method will be further extended to include wetlands in the Ngabe-Bugle indigenous reserve in Panama, and it could potentially be implemented in a network of manatee habitats in the region, such as in Mexico, Belize and Colombia, allowing for a greater comprehension of manatees’ migration patterns and regional population changes.

Future research projects, also financed by SENACYT, involve the development of a real-time detection and alert system that could continuously monitor the rivers and wetlands to prevent boat collisions, a substantial cause of manatee deaths. The team is also interested in developing advanced classification methods that would identify the sex and age range of manatees from their individual vocalizations, contributing to a better understanding of their habitat use for mating and nursing, and, ultimately, helping to inform conservation policies.

How bluehead wrasse fish change sex

This 2008 video says about itself:

Caribbean Fish Identification: Bluehead Wrasse

Bluehead Wrasse fish experience a variety of color changes and are difficult to identify. Learn to identify Bluehead Wrasse with tips from a Caribbean scuba instructor in this free tropical fish identification video.

Expert: Don Stark.

Bio: Don Stark has over 20 years of active diving experience. He has been a frequent participant on fish collecting expeditions in the Bahamas with New England Aquarium staff.

Filmmaker: Don Stark.

From the La Trobe University in Australia:

Secrets of a sex-changing fish revealed

July 10, 2019

We may take it for granted that the sex of an animal is established at birth and doesn’t change.

However, about 500 species of fish change sex in adulthood, often in response to environmental cues. How these fish change sex has, until now, been a mystery.

The secrets of fish that change sex have, for the first time, been revealed by an international collaboration led by New Zealand scientists and including La Trobe University geneticist and Prime Minister’s Prize for Science winner 2017, Professor Jenny Graves. The findings were published today in the journal Science Advances.

“I’ve followed the bluehead wrasse for years because sex change is so quick and is triggered by a visual cue,” Professor Graves said.

“How sex can reverse so spectacularly has been a mystery for decades. The genes haven’t changed, so it must be the signals that turn them off and on.”

Bluehead wrasses live in groups, on coral reefs of the Caribbean. A dominant male — with a blue head — protects a harem of yellow females. If the male is removed, the biggest female becomes male — in just 10 days. She changes her behaviour in minutes, her colour in hours. Her ovary becomes a testis and by 10 days it is making sperm.

Using the latest genetic approaches — high-throughput RNA-sequencing and epigenetic analyses — the researchers discovered when and how specific genes are turned off and on in the brain and gonad so that sex change can occur.

The study is important for understanding how genes get turned off and on during development in all animals (including humans), and how the environment can influence this process.

“We found that sex change involves a complete genetic rewiring of the gonad,” Dr Erica Todd from the University of Otago, the co-lead author, said.

“Genes needed to maintain the ovary are first turned off, and then a new genetic pathway is steadily turned on to promote testis formation.”

Co-lead author PhD candidate Oscar Ortega-Recalde, also from the University of Otago, said the amazing transformation also appears possible through changes in cellular “memory”.

“Chemical markers on DNA control gene expression and to help cells remember their specific function in the body. Our study is important because it shows that sex change involves profound changes in these chemical marks,” Mr Ortega-Recalde said.

La Trobe’s Professor Jenny Graves said the project links to studies of sex reversal in Australian dragon lizards that she is collaborating on with researchers at the University of Canberra.

“With dragon lizards the trigger for sex change is temperature, which overrides genes on the male sex chromosomes and causes embryos to develop as females,” Professor Graves said.

“Sex reversal in dragons and the wrasse involve some of the same genes, so I think we are looking at an ancient system for environmental control of gene activity.”

Hurricane season restarts in Caribbean, USA

This 16 May 2018 video from the USA says about itself:

Hurricane Season 2018 Outlook: provided by MeteoMark’s Weather Northeastern, complete with the tropical factors, total number named storms, and which areas stand the chance of seeing the greatest hurricane activity this year for the Atlantic basin, Gulf of Mexico, and Caribbean. Find out how this tropical season will stack up to last year’s 2017 blockbuster Category 5 year.

From the League of Conservation Voters in the USA, 3 June 2018:

URGENT: Hurricane season has begun, yet many are still struggling from last year’s disasters. Urge FEMA to support the continued recovery of communities of color and low income communities and commit to more equitable recovery


Hurricane season is underway, yet communities still need support to recover. Urge FEMA to support the recovery of ALL communities.

FEMA failed communities in Puerto Rico, Texas, and Florida last hurricane season – and it had deadly consequences.

While climate-fueled Hurricanes Maria, Harvey, and Irma devastated communities, the delayed, chaotic, and ineffective response of the Federal Emergency Management Agency (FEMA) exacerbated the crisis. And FEMA’s inequitable and insufficient responses disproportionately harmed communities of color and low income communities.

We cannot let this injustice continue. As the 2018 hurricane season, which we know will be made more intense by climate change, begins this weekend, it’s critical that FEMA ensures that the communities most impacted by these disasters have the resources and support to recover. Stand with impacted communities and urge FEMA to provide federal equitable recovery support before the next hurricane strikes.

We cannot adequately prepare for this hurricane season if we don’t support communities that were impacted by the 2017 hurricanes. Tell FEMA to fix systemic issues that lead to inequitable recovery

The destructive impacts of 2017’s storms, made worse by climate change, were felt first and worst by communities of color and low income communities. Many of these communities lacked the resources to prepare for and respond to these climate-exacerbated disasters.

Despite the extraordinary loss of life, property, and infrastructure, FEMA’s insufficient response failed these communities time and time again. Here are a few key examples of the egregious ways their ineffective, delayed, and insufficient responses had astounding consequences for communities of color and low income communities:

  • In Puerto Rico: According to a study from Harvard University, the death toll from Hurricane Maria was nearly 5,000 people — 70 times larger than the official government death toll of 64 people. Many of these deaths were caused by lack of medical care and insufficient access to water and electricity. And, more than nine months later, 90,000 Puerto Ricans are still without access to power. Tell FEMA to repair Puerto Rico after Hurricane Maria and ensure that this hurricane season doesn’t have the same devastating impact
  • In Texas: A Politico investigation found that historically African American and low income communities in Texas have been left behind by FEMA. Even former FEMA officials have agreed that there is a recurring and systemic problem with the delivery of federal recovery funds to most impacted communities. Urge FEMA to allocate recovery funds to the communities that need them to most
  • In Florida: In the aftermath of Hurricane Irma, the Los Angeles Times reported that Immokalee, a Floridian city comprised largely of immigrant and low-income families, was severely damaged, but received little assistance from FEMA. FEMA delayed not only in immediately responding, but also, in providing permanent shelter and housing solutions for families. Demand that FEMA respond immediately to impacted areas during the 2018 hurricane season and continue to provide long-term support to impacted families

As hurricane season begins again it’s imperative that we speak out now. If we don’t act, FEMA will continue with business as usual, even if it means that thousands of most impacted people are held in limbo. We cannot let FEMA continue to leave communities of color and low income communities behind and in danger. Raise your voice now and help elevate the critical needs of these communities to FEMA as they consider response and recovery efforts this season.

SIGN: Thousands are still struggling after 2017’s climate-fueled hurricanes. Demand that FEMA equitably support all impacted communities and prepare for more equitable support in 2018

We must ensure that ALL our communities have the vital resources they need to continue on the long road of recovery ahead.

Thank you for standing up for our communities.

Sara Chieffo
Vice President of Government Affairs
League of Conservation Voters

Policymakers are being misinformed by the results of economic models that underestimate the future risks of climate change impacts, according to a new article: here.