The Kingdom of Tonga comprises 177 islands, scattered across 700,000 sq km of the South Pacific Ocean. Geographically Tonga is composed of four major island groups, which are, from south to north: Tongatapu and ‘Eua, Ha’apai, Vava’u and the Niuas.

Tonga sits on the eastern edge of the Indo-Australian plate, which has the Pacific tectonic plate sliding under it from the east, creating the Tonga Trench. This 2000km-long oceanic valley that stretches from Tonga to New Zealand is one of the deepest in the world – if Mt Everest was placed in the deepest part of the Tonga Trench, there would still be more than 2km of water on top of it. Tonga is moving southeast at 20mm a year (geologically speaking, that's really truckin'!), meaning that the region is a particularly volatile area for volcanic and earthquake activity.

Ecology

Tonga’s national flower is the heilala, a small, pudgy pink-red bloom. The heilala, plus colourful and sweet-smelling hibiscus, frangipani and bird of paradise blooms, create dazzling roadside colours. There are coconut groves and banana plantations amid fields of taro, cassava and yams. Papaya are everywhere. Huge rain trees (kasia), mango trees and banyans dot the landscape, while mangroves smother the mudflats.

Dolphins and migrating humpback whales swim in the waters around Tonga. The humpbacks come from June to October and can often be seen offshore from the major islands.

The only land mammal native to Tonga is the flying fox (fruit bat; peka). Interesting birdlife includes the henga (blue-crowned lorikeet); the koki (red shining parrot) of ’Eua; and the malau (megapode or incubator bird), originally found only on the island of Niuafo’ou, but introduced in recent years to uninhabited Late Island west of Vava’u in an effort to save it from extinction. Butterflies are a constant delight, right across the country.

Whale-watching Ethics

Tonga is an important breeding ground for humpback whales, which migrate to its warm waters between June and October. They can be seen raising young in the calm reef-protected waters and engaging in elaborate mating rituals. Humpbacks are dubbed ‘singing whales’ because the males sing during courtship routines. The low notes of their ‘songs’ can reach 185 decibels and carry 100km through the open ocean.

Humpback populations around the world have declined rapidly over the past 200 years, from 150,000 in the early 1800s to an estimated 12,000 today. The same predictable migration habits that once made the giants easy prey for whalers nowadays make them easy targets for whale watchers.

As Tonga’s whale-watching industry has grown, so has concern over its impact. At the centre of the debate is the practice of swimming with whales. While it's undoubtedly one of the more unusual experiences you can have on the planet, some suggest that human interaction with whales – especially mothers and calves when they are at their most vulnerable – has a disruptive effect on behaviours and breeding patterns. Taking a longer view, others say that given humanity's historic propensity for slaughtering humpbacks by the tens of thousands, it's time we gave them a little peace and quiet.

In response to these concerns, in 2013 the Tongan government enacted a strict code of conduct for whale-watch operators and noncommercial yachts in the nation's waters, prohibiting unlicenced vessels within 300m of any whale, and banning swimming, diving, kayaking or jet-skiing near whales for anyone other than licenced operators.

If whale watching is a bucket-list essential for you, there are whale-watch and whale-swim operators in all of Tonga’s island groups. Vava'u has most of the operators, but Ha'apai is probably a safer bet: there are only five operators here, which equates to less pressure on the whales. Make sure you go with a licensed operator (ask at the Nuku'alofa or Neiafu visitor information centres) and give yourself a few days to do it so that there is no pressure on the operator to ‘chase’ whales in order to keep you happy. If you feel your whale-swim operator has breached the boundaries and ‘hassled’ the whales in any way, make sure you report this to the info centres.

Conservation Issues

A number of murky conservation issues cloud the waters of Tonga. These are mainly based around the environment being compromised for economic gain and include the following:

  • Swimming with dophins and whales There are arguments that swimming with whales alters their behaviour and habitat, and has a detrimental affect on both mothers and babies.
  • Green turtle conservation Tongans eat green turtles, often as part of religious ceremonies, and use turtle shell for jewellery, but turtle numbers are dwindling.
  • Sea cucumbers Asian culinary tastes mean that big dollars can be earned by exporting sea cucumbers to Asia. There is a fear that they are being overfished.
  • Aquarium fish It has been suggested that exporting brightly coloured aquarium fish to the USA is to the detriment of populations around Tongan reefs.
  • Litter Everywhere you go in Tonga you'll see piles of rubbish and non-boidegradable junk strewn along the roadsides. What a mess!

National Parks

Tonga has eight officially protected areas, including six national marine parks and reserves, Ha’atafu Beach Reserve on Tongatapu, and two national parks – the 449-hectare ‘Eua National Park and Mt Talau National Park in Vava’u.