Assalamualaikum ustaz. Is it permissible to eat dolphins?
Waalaikumussalam wrt. wbt.,
Alhamdulillah, praise and gratitude to Allah SWT for His countless blessings for us all. Praise and salutations to our beloved Prophet Muhammad PBUH, his family, companions, and all those who follow his footsteps until the Final day.
Dolphins are a type of marine mammal in the sea that is closely related to whales. It belongs to the family Delphinidae which is the largest and relatively new Cetacea family since about ten million years ago during the Miocene. There are nearly forty species in seventeen genera under the family Delphinidae.
These animals can be found all over the world. It is often found mainly in shallower areas of the sea such as on the continental shelf, however, some species live in rivers. Dolphins are considered to be among the most intelligent animals. 
Basically, all sea animals are permissible to be eaten as stated by Allah SWT:
أُحِلَّ لَكُمْ صَيْدُ الْبَحْرِ وَطَعَامُهُ مَتَاعًا لَكُمْ وَلِلسَّيَّارَةِ
“Lawful to you is game from the sea and its food as provision for you and the travellers…” 
Imam Baghawi said in his commentary saying sea life is divided into two parts:
- Fish: All types of fishes are permissible to be eaten although they are different in terms of types and shapes as narrated from Ibn Umar R.Anhuma, the Prophet PBUH said:
أُحِلَّت لنا ميتتانِ ودمانِ الميتتانِ الحوتُ والجرادُ والدَّمانِ الكبدُ والطِّحالُ
“Two kinds of dead meat and two kinds of blood have been permitted to us. The two kinds of dead meat are fish and locusts, and the two kinds of blood are the liver and spleen.” 
- Other than fish: It is divided into two parts:
- Lives on both land and sea such as a frog, then it is prohibited to be eaten,
- Only lives in water and cannot survive on land. There is a difference in opinion in this matter according to the opinion of madhhab Hanafi, all animals that live in water except fishes are impermissible. And according to the opinion of others, all dead animals that live in water are permissible to be eaten, for all of them are considered as a type of fish and they only differ in terms of physical appearance such as the eel and all aquatic life is permissible to be eaten and it is the Ittifak of scholars and also the opinion of Imam Malik and madhhab Syafie. 
From Abu Hurairah RA, the Messenger PBUH said the following when asked about the sea:
هُوَ الطَّهُورُ مَاؤُهُ، الْحِلُّ مَيْتَتُهُ
“Its water is purifying and its dead (animals) are lawful (to eat).” 
Likewise, any form of an animal of which no qat’ie evidence prohibits it is permissible. This is based on the maxim:
الأَصْلُ فِي الْأَشْيَاءِ الْإِبَاحَةُ
“The origin of something is its permissibility.”
According to the above question, dolphins are permissible to be eaten, for they are a type of fish and animal of the sea. This happened once during the time of Rasullullah PBUH when the companions found a whale on the beach, then they ate it as narrated from Jabir RA:
غَزَوْنَا جَيْشَ الخَبَطِ، وَأُمِّرَ أَبُو عُبَيْدَةَ فَجُعْنَا جُوعًا شَدِيدًا، فَأَلْقَى البَحْرُ حُوتًا مَيِّتًا لَمْ نَرَ مِثْلَهُ، يُقَالُ لَهُ العَنْبَرُ، فَأَكَلْنَا مِنْهُ نِصْفَ شَهْرٍ، فَأَخَذَ أَبُو عُبَيْدَةَ عَظْمًا مِنْ عِظَامِهِ، فَمَرَّ الرَّاكِبُ تَحْتَهُ فَأَخْبَرَنِي أَبُو الزُّبَيْرِ، أَنَّهُ سَمِعَ جَابِرًا، يَقُولُ: قَالَ أَبُو عُبَيْدَةَ: كُلُوا فَلَمَّا قَدِمْنَا المَدِينَةَ ذَكَرْنَا ذَلِكَ لِلنَّبِيِّ صَلَّى اللهُ عَلَيْهِ وَسَلَّمَ فَقَالَ: «كُلُوا، رِزْقًا أَخْرَجَهُ اللَّهُ، أَطْعِمُونَا إِنْ كَانَ مَعَكُمْ» فَأَتَاهُ بَعْضُهُمْ فَأَكَلَهُ
“We set out in the army of Al-Khabt and Abu Ubaida was the commander of the troops. We were struck with severe hunger and the sea threw out a dead fish the like of which we had never seen, and it was called Al-`Anbar. We ate it for half a month. Abu Ubaida took (and fixed) one of its bones and a rider passed underneath it (without touching it). (Jabir added:) Abu ‘Ubaida said (to us), “Eat (of that fish).” When we arrived at Medina, we informed the Prophet (ﷺ) about that, and he said, “Eat, for it is food Allah has brought out for you, and feed us if you have some of it.” So some of them gave him (of that fish) and he ate it.” 
Dolphins are included as an endangered species of marine animals
Dolphins are included in animals of endangered species. It is included in Malaysian Law, Act 686, International Trade in Endangered Species Act 2008. These marine mammals are also listed in the Fisheries Act 1985 as endangered marine species. These marine animals are also protected along with whales, dugongs, turtles, saw sharks, large white fin sharks, hammer sharks and manta rays.
To close, we conclude the following matters:
- Dolphins are permissible to be eaten according to the arguments and guidance from al-Quran and Sunnah.
- As we all know, dolphins are an endangered species. Therefore, it is our shared responsibility to ensure its survival for future generations (so that they can see and recognize it). Therefore, this coincides with Saddu al-Zarai’s maxim of closing the path that can lead to greater harm.
- In addition, dolphins are protected endangered species, that cannot be hunted or eaten according to Malaysia and International Act and legislation. Moreover, anyone convicted can be subject to legal action and punishment.
- The government has the right to decide to take care of more important issues. This is in line with a famous Islamic legal maxim:
تَصَرُّفُ الْإِمَامِ عَلَى الرَّعِيَّةِ مَنُوطٌ بِالْمَصْلَحَةِ
“Government’s policy should be based on the benefit of the people.”
- Therefore, it is the responsibility of the citizens to obey and support the ulil amri (government) in matters that are makruf (good).
May Allah SWT grant us all a clear understanding in practising this religion. Amin.
 See https://ms.wikipedia.org/wiki/Lumba-lumba (Accessed on 18th January 2022)
 Surah Al-Maidah: 96
 Narrated by Ibn Majah (3314) and Ahmad (5723)
 See Tafsir Al-Baghawi, 1/820
 Narrated by Abu Dawud (83), al-Tirmidzi (69), al-Nasaie (59), Ibn Majah (386), and Ahmad (8735)
 Narrated by al-Bukhari (4362), and Muslim (1935)