Here's what we know:
* Some species are threatened or endangered: This is due to factors like overfishing, habitat loss, and pollution.
* Others are thriving: Some species are even considered invasive in certain regions, indicating their populations are doing well.
* Data is limited: Research on many puffer fish species is limited, making it difficult to assess their population trends accurately.
Here are some specific examples:
* The Japanese Pufferfish: This species has been overfished for its use as a delicacy, leading to concerns about its population decline.
* The Northern Puffer: This species has experienced significant population declines due to habitat loss and pollution.
* The Lionfish: This species is considered invasive in the Caribbean and Atlantic, where its population has exploded.
Overall, it's important to remember that there's no single answer to the question of whether puffer fish populations are increasing or decreasing. The answer depends on the specific species and its geographic location.