Lake Natron, Tanzania and its wildlife


This video from Tanzania says about itself:

18 September 2012

The Alkaline tilapia of Lake Natron in Arusha, Tanzania. This kind of species are delicious food to … Flamingoes and Pelicans of Lake Natron in the village of Engaresero.

From BirdLife:

Irreplaceable – Lake Natron, Tanzania

By Zoltan Waliczky, 13 Oct 2016

Lake Natron is world famous for its breeding Lesser Flamingo Phoeniconaias minor, of which about half a million pairs regularly visit the lake for nesting and raising their young. There are also large numbers of other waterbirds, both migratory and resident.  Lake Natron is a shallow highly-saline lake in a closed basin on the floor of the Eastern Rift Valley. It is 1,540 km2, but only 50 cm deep. The IBA is also a Ramsar Site (wetland of international importance) but has no national protection status.

The biggest threat to the lake comes from plans to open one or more mines to exploit the rich soda ash deposits of the lake. This would not only affect the water levels and quality, and hence the breeding flamingos and other waterbirds, but also nature tourism, which is an important income generator in the wider area. In 2007-09, BirdLife led a campaign with support from the the Lake Natron Consultative Group (a coalition of 56 institutions), which successfully defeated a large-scale soda ash plant development at the site. Since then, BirdLife has implemented projects aimed at improving local communities’ livelihoods and boosting tourism.

Unfortunately, the lake is still not totally safe. Although the current government is in favour of conservation, the situation may change again in the future, so getting widespread support for conservation from local people is key to defending the lake from future attacks.

Eels’ trans-Atlantic migration, new research


This video from the USA says about itself:

Eli the eel: A mysterious migration – James Prosek

10 February 2014

View full lesson here.

They’re slippery. They’re slithery. And while they totally look like underwater snakes, eels are, in fact, unique fish that can breathe through their skin and even survive out of water. James Prosek tracks the life journey of Eli the Anguilla eel as she (yes, she) travels her mysterious “backward” migration from the sea to fresh water and back again.

Lesson by James Prosek, animation by Cinematic.

From Science Advances:

Empirical observations of the spawning migration of European eels: The long and dangerous road to the Sargasso Sea

5 Oct 2016

Abstract

The spawning migration of the European eel (Anguilla anguilla L.) to the Sargasso Sea is one of the greatest animal migrations. However, the duration and route of the migration remain uncertain. Using fishery data from 20 rivers across Europe, we show that most eels begin their oceanic migration between August and December. We used electronic tagging techniques to map the oceanic migration from eels released from four regions in Europe. Of 707 eels tagged, we received 206 data sets.

Many migrations ended soon after release because of predation events, but we were able to reconstruct in detail the migration routes of >80 eels. The route extended from western mainland Europe to the Azores region, more than 5000 km toward the Sargasso Sea. All eels exhibited diel vertical migrations, moving from deeper water during the day into shallower water at night.

The range of migration speeds was 3 to 47 km day−1. Using data from larval surveys in the Sargasso Sea, we show that spawning likely begins in December and peaks in February. Synthesizing these results, we show that the timing of autumn escapement and the rate of migration are inconsistent with the century-long held assumption that eels spawn as a single reproductive cohort in the springtime following their escapement.

Instead, we suggest that European eels adopt a mixed migratory strategy, with some individuals able to achieve a rapid migration, whereas others arrive only in time for the following spawning season. Our results have consequences for eel management.

Young eels take over three years to migrate from the Sargasso Sea to Europe. They have to be careful to not be eaten by sharks, whales or sea lions.

Eels may not take most direct route in epic ocean-crossing spawning runs. Meandering swims mean some fish may start journey one breeding season, spawn the next, tracking data suggest. By Susan Milius, 2:08pm, October 5, 2016: here.

Coral reefs, parrotfish poop and sand


This video says about itself:

Parrotfish Poop! | JONATHAN BIRD’S BLUE WORLD Extra

23 September 2016

In this short Jonathan Bird’s Blue World Extra, Jonathan discusses where sand comes from and you may be surprised to learn that a lot of sand is actually fish poop!

Jonathan Bird’s Blue World is an Emmy Award-winning underwater science/adventure program that airs on public television in the United States.

Osprey catches flatfish, video


This 21 September 2016 video shows an osprey catching a flatfish, near Oostvoorne in the Netherlands.

Diego Jansen made this video.

Dutch North Sea reef underwater wildlife, video


This 16 September 2016 is about the Dutch North Sea reef Borkumse Stenen, its fish, tube worms, soft coral, sea anemones and other underwater wildlife.

World’s oldest fishhooks discovered


World's oldest fishhooks, photo National Academy of Sciences

Translated from Dutch NOS TV:

Fishhooks, oldest in the world, found in Japan

18 September 2016

Archaeologists have found the oldest fishhooks in the world in Japan. They were in a cave on Okinawa island and are estimated to be 23,000 years old.

The hooks are made from a sea snail‘s shell. From this discovery archeologists conclude that fishing techniques have existed already much longer than expected, and were used in more places in the world.

Eels and frogs

Okinawa was first inhabited around 35,000 years ago. Scientists wondered how people there survived all the time. The fishhooks have answered that question.

In Sakitari cave researchers found also remains of eels, frogs, birds and small terrestrial animals. They conclude from that these were also on the menu of the first inhabitants of Okinawa.

East Timor

Until now, scientists assumed that the fishhook was invented about 16,000 years ago.

They based themselves on a find in East Timor in 2011. In the northern part along the coast hooks were found which were made of shellfish.