Complex sentence: Valuable foreign earnings come from the royalties from the commercial crawfish or Tristan rock lobster (Jasus) industry and the sale of postage stamps and coins, especially to collectors worldwide.
Split into simpler sentences: Valuable foreign earnings come from the royalties from the commercial crawfish or Tristan rock lobster (Jasus) industry. Other revenues are derived from the sale of postage stamps and coins, especially to collectors worldwide.