Picture of a smalltooth sawfish, Pristis pectinata, endangered
Picture of a smalltooth sawfish or wide sawfish, Pristis pectinata, endangered, Everglades National Park, Florida Gulf of Mexico
Not only are these different species, they are fished from different parts of the ocean. Goliath Grouper tend to congregate in the big holes in the limestone shelf or near bridge pilings. Tuna are deep water fish. Permit are trophy fish for flats fisherman. Small snapper are often caught close to shore, though you have to go out deep for the really big ones. (Oddly, none of these pictures show swordfish (Papa Hemingway's favorite)or Tarpon, which are favorites of trophy fishermen.) So, no, this isn't apples to apples, but all these fish are in need protective limits or a ban on commercial fishing as has been done for the Goliath Grouper and snook.
people for the most part do not keep really big fish anymore... While lots of fish are documented as getting smaller (most notably bluefin tuna) these pictures do not really show anything worth noting except for peoples change in conservation attitudes. 60 years ago it was not uncommon for people to kill everything they catch, now with increased regulations and changing attitudes among sportsmen it would be less likely for people to kill really big fish.
pictures of small fish | Should you keep it
Picture of a whale shark with small fish.
How much smaller? Adjusting for time of year, and after checking and measuring 1,275 different trophy fish, she found that in the 1950s, the biggest fish in the photos were typically over 6 feet — sometimes 6 feet 5 inches long. By the time we get to 2007, when Loren bought a ticket on a deep sea day cruise and snapped this picture ...Several people have pointed out that different species of fish seen in the pictures seems to negate them as evidence of overfishing or change. In fact, the species composition is part of the story. The idea of shifting baselines and fishing down the food web go hand-in-hand. Healthy marine communities are "top heavy", that is in pristine systems the bulk of the biomass is in large, apex predators. As systems are exploited these top-tier species decline in abundance and smaller species from lower positions in the foodweb become dominant. As a result, once one desirable species has been exploited, another species is targeted to fill the void. While the protection status of Goliath groupers may makes this less clear (keep in mind the frequency of people actually hooking Goliath in the lower Keys is still much lower than in the 50's and 60's), the shift from big Jacks and Permit in the 4th picture to mostly Yellowtail snapper in the most recent picture speaks clearly to the problem.