Not necessarily true that Arab and Indian grocery stores sell only halal products , and then you have to be careful about Stores owned by Christian Arabs , there is a Zaid Market in Anahiem , CA . Which smells , looks like and sounds like an Arab store but they sell pork too. 
It is owned by a Christian Arab.
As per some Islamic scholars all seafood is halal: here are the references they use for their stance:
Al Quran
Surah AN_NAHL (The BEE)
16:14 It is He Who has made the sea subject, that ye may eat thereof flesh that is fresh and tender, and that ye may extract therefrom ornaments to wear; and thou seest the ships therein that plough the waves, that ye may seek (thus) of the bounty of Allah and that ye may be grateful.
Surah FATIR (the Angels, originator)
35:12 Nor are the two bodies of flowing water alike,- the one palatable, sweet, and pleasant to drink, and the other, salt and bitter. Yet from each (kind of water) do ye eat flesh fresh and tender, and ye extract ornaments to wear; and thou seest the ships therein that plough the waves, that ye may seek (thus) of the Bounty of Allah that ye may be grateful.
Hadith
Abu Hurairah narrated that a man asked the Messenger of Allah( peace be upon Him) “O prophet(s) , we sail on the ocean and we carry only a little water if we use it for ablution , we will have to go thirst , May we use it sea water for ablution? " Said Prophet (S)” Its ( the sea) water is pure and its dead (animals) are lawful(i,e, they can be eaten without any prescribed slaughtering)
Tis Hadith is related by “the five” .At Tirmizi calls it hassan sahih. and Al Bukhari says it is sahih.
Not so fast.
Read this news article:
Gulfnews: Many American meat exporters obtain halal certificate fraudulently
Many American meat exporters obtain halal certificate fraudulently
By Nadia Saleem, Staff Reporter
Published: November 13, 2008, 23:54
Dubai: Ninety-five per cent of American food items found in supermarket shelves in the UAE and some other Gulf countries are not halal even though they may be certified as such, an industry specialist said at the Halal World Expo in Abu Dhabi.
Jalel Aossey, director of Midamar, a US-based international supplier of halal food and foodservice equipment, said that there is a significant flow of non-halal food items in the region from meat-supplying countries, and the Gulf countries need tougher regulations to stop that flow.
“On one side you have producers who genuinely don’t know what they have to comply with because of a lack of education from the industry. But you also have companies and exporters that are deliberately defrauding governments and consumers by not complying with regulations because they don’t want to pay the fees and the transition costs to make halal products,” Aossey said.
Corrupt certifiers
Nearly 1.8 billion Muslims around the world as well as some non-Muslims are fuelling the halal food industry, generating sales of $2.1 trillion annually, according to recent reports. The attractive halal food industry is drawing many dubious players.
“Corrupt certifiers get a taste for the money generated producing “paper halal certificates” for companies without actually performing any work,” Aossey said.
On regulatory measures, Aossey said, “People have to realise that it is not impossible, and that it’s not too costly to put the correct halal standards in place here. There’s a big misconception about how difficult this process is.”
Noor Al Deen Abdullah, executive director of Kasehdia, a communications and consultancy company in Malaysia, and publishers of The Halal Food Journal earlier told Gulf News, “The global halal industry is still in its infancy because huge awareness is required, especially in the Middle East.”
The major producing nations are Australia, New Zealand, Brazil and Canada, Abdullah said, from where halal and non-halal meat is supplied.
Aossey said that inspection teams can be sent to the various countries where food is being produced to allow it to be inspected, at that country’s cost. “This is nothing when you consider the huge dollar volume of food products exported to the UAE and other Gulf countries.”
In the UAE, 80 per cent of imported food is said to be halal, coming from countries such as Brazil and Australia.
facts
What is halal meat?
Halal (or permissible) in Islam is the meat of animals that have been slaughtered reciting the name of Allah on them and all the blood has been drained from the carcass.
Additional criterion that make meat halal are that the animal should not be dead prior to slaughter, since carrion is forbidden and that the animal is from those that are allowed according to Islamic teachings.
