70 years of helping people to care for our ocean

The 90th iSimangaliso surf-zone fish monitoring and tagging field trip

By Bruce Mann 

The 90th iSimangaliso surf-zone fish monitoring and tagging field trip was conducted at Sodwana from 15-18 February 2022. The weather was typical of February with hot, humid conditions. The wind wasn’t too bad with moderate easterlies, except for the strong south-westerly on Thursday which gusted to over 25 knots. The swell ranged between 1.8 and 2.5 m and the water temperature was a very warm 27-28°C. The team included James Turner (JJ), Wesley Dalton (WD), Arthur Mann (AM), Gareth Jordaan (GJ), our old friend Stuart Dunlop (SD) and guest angler Chris Bachle (CB), who took off a week from school and flew up from George to fish with us.

Team leaders were Rob Kyle (RK) and me (BQ). For safety reasons we again decided that the two teams should fish together on this trip. During the trip, we caught a total of 233 fish of which 133 were tagged, 4 were recaptures and 96 were small fish or non-tagging species. The recaptures included 2 speckled snappers, 1 potato bass and our first bigspot rockcod recapture. The fish with the longest time at liberty was a speckled snapper originally tagged on 10 February 2017. During its 1834 days (5 years) at liberty, this fish stayed in much the same place and grew 80 mm. The fish that grew the most was a potato bass tagged at 386 mm TL and recaptured at a length of 715 mm TL, a remarkable growth rate of 82 mm/year. On Monday 14 February before we had officially started, Rob Kyle recaptured a bluefin kingfish of 580 mm FL off Jesser Point. This turned out to be the same fish that he had tagged last year in exactly the same spot.

Since our last Sodwana trip in February 2021, we have had a further two recaptures reported to us by members of the angling public including a yellowbelly rockcod recaptured at the same spot at Adlams by Kevin Rudolph and a speckled snapper that was tagged at Adlams  and recaptured by subsistence fisherman Thabiso Mthembu near Kosi mouth, a remarkable distance of 77 km! Again, Rob topped the log, followed by Stuart and Arthur. A total of 122 fish (52.4%) were caught in the two no-take wilderness areas , while 111 fish (47.6%) were caught in the two exploited areas.  In terms of catch rates, the catch per unit effort (CPUE) in the no-take areas (1.08 fish/angler/hour) was nearly double that achieved in the two exploited areas (0.66 fish/angler/hour). However, this was biased by the large number of small largespot pompano and grey grunter that we caught in the no-take areas and because we only fished a half day due to the strong SW wind that came through on Thursday. Generally, the fish were reluctant to take bait, but fair numbers of pompano and small kingfish were caught on lures. Unfortunately, there was still much evidence of poaching taking place in the no-take wilderness area with numerous fishing spot markers on the beach and lost tackle found in the rocks at low tide. Again, we implore the authorities to do their best to stamp out this illegal activity.

A total of 27 fish species were recorded on the trip with 21 species caught in the exploited areas and 17 species caught in the no-take areas. No new species were recorded, so the total species count for the project remains at 116 species to date. Species composition was dominated by largespotted pompano (80), grey grunter (49), speckled snapper (31), giant kingfish (9) and cave bass (7). Several big fish were caught during the trip including a honeycomb ray of 1090 mm DW (35.6 kg) caught by Chris, my personal best GT of 1200 mm FL (33.4 kg) and two giant sandsharks of 1720 mm TL (28.6 kg) and 1420 mm TL (16 kg) caught by myself and Rob respectively.

If you have not done so already, please check out our new ORI Fish App (Marine Fish Guide for Southern Africa for both Android and iPhone) for easy access to information on linefish, including a length/weight calculator.

https://www.saambr.org.za/marine-fish-guide-for-southern-africa-app/