Rian Nathani’s review published on Letterboxd:
Emotionally manipulative and bereft of any sort of intellectual nuance, Seaspiracy is also too often unfocused and does not offer any substantive but reasonable solution beyond rote, blanket statements. Doesn't help that the director is one of the most annoying subjects of a documentary I've ever seen - his presence is incredibly unhelpful to the message the film is aiming for. He just comes off as a bit of a self-important dunce, and fairly amateurish to boot. But my two primary criticisms are these:
1. So many of the interview subjects in this film wave and shout and stare meaningfully at the camera while proclaiming that NO ONE is working on, or even talking about, some of the issues at hand here (for example, bottom trawling). All I can gather from these repeated instances is that the filmmakers and their subjects are choosing to ignore the fact that there are several prominent organizations out there that are, in fact, working on issues like bottom trawling, and even a modicum of research on the subject would demonstrate that. As someone with experience in this field it comes off as incredibly stupid and tarnishes their credibility.
2. Most insultingly to me, however, is the fact that some sections of Seaspiracy pretend to be breaking new ground and shining a light on situations that in fact have been the subjects of entire films themselves. The filmmakers' trip to Taiji, Japan early in the film is just a poor retread of the far-superior The Cove, and it's not even mentioned. Furthermore, the filmmakers take great pains to make you think they're so brave for traveling to Bangkok to interview victims of the Thai fishing slave trade, but are so carried away by their own actions that they neglect to mention whatsoever the work being done by local advocates such as Patima Tungpuchayakul, who was spotlighted so powerfully in the film Ghost Fleet. Both the Japanese dolphin hunt and the Thai fishing slave trade are so important to bring awareness to, but neglecting to credit the filmmakers who have come before you (and done what you tried to do more effectively than you) is so intellectually dishonest.
This film is going to get a lot of attention and will probably be highly regarded by many, and it's the right of everyone to feel however they want about it. But the filmmakers get a lot wrong here and a little more research into fisheries issues and the greater problems that face our oceans would go a long way.