2.Tonga

Why in the news?

• Pacific island leaders gather for a key summit in the Kingdom of Tonga, aiming to navigate rapidly rising seas, damaging great power rivalries and violent unrest in New Caledonia. 

About Tonga:

• It is an island country in Polynesia, part of Oceania. 
• The country has 171 islands – of which 45 are inhabited.
• Its total surface area is about 750 km2 (290 sq mi), scattered over 700,000 km2 in the southern Pacific Ocean.
• 70% of its population reside on the main island, Tongatapu. 
• It stretches approximately 800 km north-south. 
• It is surrounded by:
  • Fiji and Wallis and Futuna (France) to the northwest
  • Samoa to the northeast
  • New Caledonia (France) and Vanuatu to the west
  • Niue to the east
  • Kermadec (New Zealand) to the southwest
• It is about 1,800 km from New Zealand's North Island.

3.Humpback Whales

Why in the news?

• Researchers have now found that humpback whales do not just create the ‘bubble-nets’ but they manipulate this unique tool in a variety of ways to maximize their food intake in Alaskan feeding grounds. 
• The humpback whales skillfully blow bubbles in patterns that form nets with internal rings, actively controlling details like the number of rings, the size and depth of the net, and the spacing between bubbles. 
• This method lets them capture up to seven times more prey in a single feeding dive without using extra energy.

About Humpback Whales:

• These are one of the four species of baleen whales.
• They are large, toothless whales that have baleen plates to filter their prey from seawater.
• They have streamlined bodies ranging from 6 to 33 m in length., reaching up to 17 m in length and over 30,000 kg in weight.
• They occur worldwide in all major oceans. While they generally demonstrate a preference for continental shelf areas, they are also known to cross deep offshore waters, and spend time over and around seamounts in the open ocean.
• Their IUCN status is least concerned.
• Migration
  • Humpback whales with the exception of the endangered Arabian Sea population perform some of the longest migrations of any whale species, swimming up to 10,000 km each year.
  • They migrate because they feed and breed in very different places.
  • In the Southern Hemisphere, humpback whales spend the summer in the cold waters of Antarctica, feeding on Antarctic krill, which are small shrimp-like crustaceansAnimals with a hard outer body made up of different sections e.g., crabs, prawns, barnacles. which live in large groups called swarms.
  • In the wintertime, humpbacks migrate north to mate and give birth in warmer, subtropical waters.
  • The Arabian Sea humpback whales are the only sedentary whales in the world, feeding and breeding in the same area.

4.Zika virus

Why in the news?

• The Institute of Advanced Virology, Thiruvananthapuram, has developed an assay for Zika testing using the sequence data made available by CDC and validated the assay using clinical samples, commercial tests and genome sequencing. 

About Zika virus:

• It is a mosquito-borne flavivirus that is primarily spread by Aedes mosquitoes, particularly Aedes aegypti.
• Also, it can also be transmitted from mother to fetus during pregnancy, as well as through sexual contact, transfusion of blood and blood products.
• It has an RNA genome, and thus a very high potential to accumulate mutations.
• Genomic studies have suggested that the Zika virus has two lineages: African and Asian.
• History: 
  • This virus was discovered in 1947 in the Zika forest in Uganda from infected monkeys, the first human cases were recorded in 1952 in Uganda and Tanzania.
  • Outbreaks have occurred across Africa, the Americas, Asia, and the Pacific since 2007.
  • Notable outbreaks have occurred in Indian states like Kerala and Karnataka in recent years.
• Symptoms:
  • It is often asymptomatic. 
  • When present, its common symptoms include fever, joint pain, muscle pain, and headache lasting 2-7 days.
• Association with Other Conditions: 
  • It is linked with Guillain-Barre syndrome, neuropathy, and myelitis in adults and children.
  • Also, the interaction between Zika and dengue viruses significantly impacts disease severity.
  • Exposure to one can worsen the impact of the other, posing challenges in vaccine development and public health management.
• Complications: 
  • Infection during pregnancy causes congenital malformations, such as microcephaly and other associated conditions.
• Treatment and Prevention: 
  • There is no specific treatment available. 
  • Symptomatic relief and medical care advised for worsening conditions.
  • No vaccine available yet; prevention focused on mosquito bite protection, eliminating breeding sites, and public health initiatives to control mosquito populations.