Now I am laughing. Every study I have seen done up here usually comes to the conclusion that they need more $ to study longer because they got more questions than answers.
They have been studying salmon for years, yet still have zero idea on what is eating/killing the Kings. The one statement we continue to hear is that is not fresh water, but ocean survival. That statement coupled with the one that "Chilkat Fish are inland feeders", (meaning they stay within the southeast Alaska waters), but they don't attribute the increase in whales, seals, sea lions, improvements in fishing effectiveness and multi million hatchery fish released in the southeast waters as a problem.
We can control one variable- amount of fishing pressure. But we don't.
The more we know, the more we know how little we know.
And scientific studies present more questions than answers - that's just the nature of studying complex natural systems. So yes, more money will be needed to answer these new questions, which will then present more questions, which will then need more money. But the rewards are worth it.
It may also appear that there is conflicting information coming out of these studies, but let's take Chinook salmon as example using some very, very rough numbers:
A female lays 5,000 eggs on average (varies by female weight and can be as much as 10,000 or more).
The egg to smolting survival is about 7% (varies by stock/stream, water temperature/flow, density of spawners, weather, etc.)
Smolt to adult returning survival is about 2% (well it used to be, but now it's less than 1% for some stocks and is dependent on lots and lots of factors).
There are a number of studies that look at various causes of mortality at every life stage, and sometimes the answers may appear conflicting because many factors are interacting in ways that are hard to predict.
For example, increased fresh water temperature increases metabolic rates and growth of the fry but if there is little food, then their mortality increases, otherwise with sufficient food, they grow bigger, increasing their survival.
Then there are predator-prey interactions - and answers to questions such as what happened to the herring? What is the effect of changing prey field on Chinook salmon survival?
And then my field of studies - adaptive plasticity and population resilience due to standing genetic variation, meaning if and why some populations are able to adapt better than others. For example, why some Chinook stocks are affected so differently by the recent marine heat waves?
The list is almost endless.
Like you said, we can control amount of fishing pressure, but seeing and understanding the whole picture is not without merit either.