Late in the day, Piya spots a fishing boat. She's spent hours already standing in the front of Mejda's boat, surveying the water. She hasn’t spotted any dolphins, though she did notice a group of four massive crocodiles. Piya is perplexed; she's in the exact region where she should find dolphins. She also hasn't seen any fishing boats, which means she hasn't been able to ask local fisherman for advice. Piya wonders if the area is off-limits for fishing. She pulls out her rangefinder and discovers that the fishing boat is just over a kilometer away. She thinks the fisherman (later revealed as Fokir) looks old and experienced, so she decides to see if Mejda will stop.
Mentioning the crocodiles makes it clear that the Sundarbans aren't a safe, friendly place to be out on the water, given that massive and aggressive creatures abound. When combined with Mejda's previous predatory behavior, this suggests that Piya is not just going to have to fight the natural world to survive—she'll have to go so far as to fight the humans that populate it, too.
When Piya points out the boat and asks for a detour, she notices that the forest guard looks suddenly predatory. Mejda turns his boat towards the fishing boat, and Piya believes they aren't just going because she asked. She watches Fokir through her binoculars and sees the moment he notices her approach. She notices there's a child with him. Looking terrified, Fokir begins to row towards a small creek edged by mangroves. Piya has never seen an escape attempt like this before, but notices that the guard has his rifle out. She angrily tries to wave the guard away, but Mejda pushes the engine of the boat faster. When Piya tries to approach the guard again, he elbows her in the collarbone and sends her reeling.
Here, when the guard elbows Piya and sends her flying, his actions speak far louder than any words he could say: he doesn't value Piya's life or her work; he prizes his ability to intimidate others, Fokir included. It's also worth noting that here, the gun is something that Piya reads as a symbol of power and the thing that really raises Fokir's suspicions. This again suggests that visual cues like the gun or Piya's flashcard are far more effective forms of communication than spoken language.
Fokir finally tethers his boat to Mejda's, and the forest guard points to Fokir and says, "poacher." Piya is shocked to see that Fokir is in his late twenties, and even more shocked when the guard motions for Piya to show him her flashcard. Shocked to see a woman, Fokir wraps himself in a sarong, which Piya finds strangely comforting. When she shows him the card, he points upriver. She motions for him to point to which dolphin he's seen, and is surprised when he points to the rarer Irrawaddy dolphin and holds up six fingers.
Again, when Fokir's actions convey that he respects Piya and is willing to care about what she cares about (the dolphins), it shows that at least in this instance, these nonverbal forms of communication are far more effective at getting points across than spoken language. It's telling too that Fokir offers more information than he's asked for; that indicates a true desire to communicate.
Looking up, Piya notices that the forest guard has boarded Fokir's boat and is taking money from the child (Tutul). After the guard climbs back to Mejda's boat and the engine starts, Piya surreptitiously pulls money out of her belt and tries to give it to Fokir. She climbs onto a chair as to throw the money, catching the attention of both the guard and of Fokir, and she falls into the muddy water.
Here, the money acts as another way for Piya to tell Fokir that she recognizes his humanity and believes he's worth more than the forest guard seems to believe. In this way, it also becomes a symbol for modes of communication that don't require a shared spoken language.