Niue, a sovereign state in free association with New Zealand, uses two official legal tender currencies. The New Zealand Dollar is the circulation currency for daily transactions, while the government also authorises legal tender coins in the Niue Dollar currency for collector's purposes.
A number of mints issue a large variety of commemorative, bullion and collector coins under the authority of Niue. These coins are dedicated to historical or general popular culture themes not related to Niue itself.
Some coins are marketed in standard bullion sizes, like half ounce silver, one ounce silver etc, and some of those are also denominated as $1, for which see respective lists. This coin, denominated as One Niue Dollar, is not in a standard ounce-based size and is made using a "smartminting" technique - meaning that it has features not generally found in circulation coins.
This coin is part of the Endangered Animal Species series and features the Blue Whale.
The Mint says about it:
"The Mint of Poland is proud to present the last, tenth coin from the series "Endangered Animal Species", devoted to the Blue Whale - the biggest mammal of all times.
This unique coin reminds us how fragile is the beauty of animals being on the verge of extinction. Blue whales were almost hunted to extinction by whalers attracted by their enormous size. These impressive marine mammals have been classified as critically endangered, and thanks to this decision their population is now slowly recovering." | 
Search for Niue: One Dollar Silver 2015 Blue Whale on eBay 
