The 36-year-old fishing guide, whose family owns 400 acres on the Madera County side, has been fishing, boating and swimming in the river since he was a boy.
Piloting his 14-foot aluminum skiff up river, Moosios keeps the 40-horsepower outboard's throttle steady through a series of bends and side channels, and even across a small weir.
"I've snorkeled the entire river from [Freeways] 41 to 99 -- that's how you get to know every little turn, every little bush, every big rock and fish hiding spot there is," Moosios says.
By now, everyone should be aware Chinook salmon are slated to be reintroduced to the San Joaquin, perhaps as soon as this year. And like in other California rivers where salmon have been re-established after a long absence, those fish will either be off limits to anglers or strictly catch and release.
But what seems to be lost in all of this, even though it's spelled out in the Draft Environmental Impact Report, is that the presence of salmon will also mean the end of all trout fishing and, potentially, bass fishing.
No more trout fishing in the San Joaquin? It says so right in Section 3.3 of Chapter 21, which quotes California Fish and Game Commission policy: "Domesticated or nonnative fish species will not be planted, or fisheries based on them will not be developed or maintained, in drainages of salmon waters, where ... they may adversely affect native salmon populations by competing with, preying upon or hybridizing with them."
Think about what that means for a moment.
No more trout plants at Lost Lake Park or North Fork bridge, the two most popular spots on the river.
No more trout derbies at the Fresno County Sportsmen's Club.
Thousands will have to go elsewhere.
The report states that 18,000 anglers use Lost Lake Park every year. What are all those people supposed to do now? Simple, it concludes: They'll just have to go to the Kings River instead.
Even though the report lists the impact on trout fishing as "potentially significant," I'll bet this is the first you've heard of it.
By the time the San Joaquin flows into Fresno, where Moosios and I are spending the afternoon, it becomes a warm-water fishery inhabited by bass, crappie, bluegill and catfish. And, yes, the fishing for those species will be affected as well.
Most of the best bass fishing takes place in reclaimed gravel quarries. But the report states these ponds, and there are many of them, must either be filled in or separated from the river so that juvenile salmon don't get swallowed by predators.
What happens to the fish in these ponds when their habitat gets cut off from the river? Water levels, temperature and quality are impacted to the point where "fish populations may decline or may be eliminated over the longer-term if conditions for fish deteriorate."
Guess that means no more bass fishing in the San Joaquin, either.
This is where Moosios has a problem, noting that most of the river's invertebrates and insects, potential food sources for salmon, are produced in these ponds, then flushed into the river.
Isolate all the ponds from the river, and you're affecting the health of the river as well.
"They need to do a lot more research before they separate these ponds from the river," Moosios says in between casts. "They might be spending money in one place that costs them even more in another."
Even without salmon, the river restoration has already adversely impacted fishing. To demonstrate, Moosios steers us toward a gravel bar. Once we get out, I immediately notice dozens of saucer-shaped clusters of pebbles.
Moosios explains these are bluegill nests, established when the river was running high. But one night a couple of months ago, during mid-spawn, water levels dropped, leaving the entire colony high and dry.
"When they dropped the river, millions of bluegill fry in these nests dried up and died," Moosios says. "People like to catch bluegill, and these nests could've repopulated the whole river."
Whether guiding clients or fishing by himself, Moosios spends several days a week on the San Joaquin. More than anything, he fears that having salmon in the river will bring out the worst kind of people: poachers.
Moosios has plenty of first-hand experience with poachers. He's caught people trespassing on his property carrying 100-pound stringers. He's seen people use a car antenna and surgical tubing to make homemade spears called Hawaiian slings. He's found fishing lines tied to bushes with baited hooks just left in the water. He's seen gill nets strung across the entire channel, entangling every fish that happens by.
What'll happen when salmon are present? Moosios practically shutters at the thought.
"The poaching is going to go crazy," he says. "People are going to see these fat salmon in the river, and they're not going to be able to help themselves. The only way they're going to stop it is if [the Department of Fish and Game] puts a full-time warden on the river between Friant and 99."
Given California's budget woes, and the fact that the DFG is already vastly underfunded, good luck with that.
Before we exit the pond and try our luck in the river -- where Moosios uses a crankbait to catch and release a 4-pound spotted bass, a female plump with eggs -- he has one more thing to show me.
In November, you might remember hearing about a large deer that went for a run through northwest Fresno before being captured in someone's garage. Three local TV stations carried the story with all the requisite cuteness.
"Since that story was on the news, I've been noticing more people on the river with bows and guns," Moosios says. "That's probably what happened to this animal."
Glancing down alongside the boat, a disturbing image begins to take shape. It's a large deer with its head chopped off. The carcass just lays there, half submerged. Hard to imagine a more pitiful sight.
If a 200-pound deer can be poached, in full view of a line of luxury bluff homes, salmon don't stand a chance.