Population Dynamics Parameters and Exploitation Status of 55 Commercial Species in Egyptian Red Sea Fisheries: A Key to Sustainable Fisheries

Abstract

Egyptian Red Sea fisheries face the same challenges as most of the world’s fisheries, including overexploitation, habitat loss, IUU fishing, pollution, and climate change. These fisheries are highly diverse with multiple species targeted by multiple fleets, using different fishing gears. Much work has been performed in recent years to assess Red Sea fish stocks. However, not all fish stocks in the Egyptian Red Sea are assessed, and those that are assessed only cover 30% of landings. The assessments are unbalanced by area, with the Gulf of Suez being much better covered than the southern Red Sea and Gulf of Aqaba. The results show that most of the analyzed stocks are overexploited. There is an urgent need to take action to protect, conserve, and restore the different fish stocks in different fishing grounds. These actions will ensure the sustainability of the fisheries, making them ecologically friendly and economically and socially efficient.

1. Introduction

The Red Sea, a tropical sea with a rich history and unique marine ecosystem, is home to a wide variety of fish, many of which are of great commercial importance [1,2,3]. However, the unsustainable exploitation and illegal, unreported, and unregulated fishing (IUU) of these species threatens the health of the ecosystem and the long-term viability of the fishery [1,2,4]. Despite a growing demand for fishing resources due to population increase and a hard economic situation, sustainable management remains a major challenge for Egypt [5,6,7]. Understanding the biology of these species is essential to ensure the sustainability of fishing and the conservation of the marine ecosystem.

The Red Sea (Figure 1) is an elongated narrow sea between Northeastern Africa and the Arabian Peninsula, between 30° N and 12°30′ N and from 32° E to 43° E, with a straight-line length of about 2000 km and an average width of 208 km [5]. The Red Sea is connected to the Indian Ocean in the south through the narrow strait of Bab al Mandab. It has an average depth of 491 m, with a maximum depth of 2850 m. In the north, the Red Sea is divided into the Gulfs of Suez and Aqaba. The Red Sea is characterized by a few unique oceanographic and biological structures and is considered a hotspot for coral reef ecology. It also boasts high fish diversity, with more than 1400 species of fish reported in FishBase (www.fishbase.org, accessed on 1 April 2024).

Three main fishing methods are deployed in Red Sea fisheries: bottom trawl, purse seine, and artisanal ones. Bottom trawls constitute about 20% of Egyptian Red Sea fisheries, forming about 54% of the gross revenue due to the high price of some demersals caught by it, such as shrimp and cephalopods. Purse seine constitutes about 68%, and the artisanal fishery contributes the remaining 12% of the Red Sea catch in Egypt [1].

This study aims to provide up-to-date scientific information on the biological parameters of more than 50 commercial fish species from the Red Sea, including data on catch, areas fished, as well as basic data on the biology and dynamics of these species, thereby contributing to sustainable fisheries management and the conservation of marine biodiversity in this unique region. In the absence of information in this regard, this contribution is the first attempt to compile population dynamics parameters and the exploitation status of 55 fish species in the Egyptian Red Sea. This information will provide a solid basis for assessing the current status of fish stocks and establishing reasonable catch limits.

2. Material and Methods

The Egyptian sector of the Red Sea (Figure 1) is about 1080 km long, extending from Suez City in the north to Mersa Halayeb in the south. Numerous fishing grounds are found along the Egyptian Red Sea, yielding an average annual catch of about 48 thousand tons [8]. The Egyptian Red Sea is divided into three main fishing grounds: the Gulf of Suez, the proper Red Sea (from Hurghada to Halayeb, including Foul Bay), and the Gulf of Aqaba. Several landing sites are located along the Egyptian Red Sea, including Ataka, El-Tor, Nuweiba, Hurghada, Safaga, Quseir, Berenice, Shalateen, and Abu Ramad. Additionally, Egypt has signed treaties with its neighbors to allow fishing in their territories (Figure 2).

The most common fishing gears used in the Red Sea by Egyptian fishermen are bottom trawls and purse seines (industrial fishery), hand lines, long lines, and gillnets (artisanal fishing), along with a variety of gears used by some of the traditional coastal communities. The industrial fishing fleets operate primarily in the Gulf of Suez and its neighboring areas, as well as Foul Bay. Semi-industrial fleets concentrate near Ataka, Salakhana, Hurghada, and El-Tor. Small-scale fisheries are common in Safaga, Quseir, Shalateen, and Abu Ramad [1].

This study relies on fishery statistics from the General Authority for Fish Resources Development (GAFRD) annual statistical book of 2021. Bimonthly field trips lasting at least seven days each have been carried out routinely since 1999 by the Fish Population Dynamics Lab, National Institute of Oceanography and Fisheries (NIOFs), to cover all fishing grounds along the Egyptian Red Sea. During these field trips, fish samples were collected directly from commercial fishing boats, and interviews were conducted with fishermen working in the area. This study analyzes data collected over the past ten years (2014–2024) in the Egyptian Red Sea with its two gulfs (Figure 1). This study focused on landings at the following locations: Ataka and El-Tor in the Gulf of Suez; Hurghada, Berenice, Shalateen, and Abu Ramad in the proper Red Sea; and Nuweiba and Dahab in the Gulf of Aqaba. In addition, the population parameters were compiled from two sources: previously published works and new estimations by the authors of this study for specific species.

Estimates of the asymptotic length (L∞) and the growth rate (K) were obtained using the ELEFAN program (Electronic Length Frequency Analysis) within TropfishR [9] for R statistical program version 3.6.3 [10].

Analysis of the cumulative catch curve [11] and of the length-converted catch curve [12] was used to estimate the total mortality coefficient (Z).

Natural mortality (M) per age was estimated using an online tool (barefootecologist.com) with three empirical formulae. Fishing mortality (F) was then determined as Z − M.

The exploitation status (E) was calculated as E = F/Z, where F is the fishing mortality rate.

The exploitation rate (E) is crucial for evaluating a fish stock’s status as optimal, underexploited, or overexploited. According to Gulland (1971), a stock is considered optimally fished when fishing mortality (F) equals natural mortality (M). In simpler terms, an exploitation rate (E) of 0.5 indicates optimal fishing pressure.

3. Results and Discussion

3.1. Landings and Catch Composition

Official annual landings of the Egyptian Red Sea fluctuated between 43.6 and 51.5 thousand tons from 2012 to 2021, averaging around 48 thousand tons. Red Sea fisheries account for about 11.5% of Egypt’s total landed catch from natural resources, generating an estimated revenue of EGP 6.35 billion. Figure 2 and Figure 3 illustrate the contribution of different fishing grounds to the Red Sea’s total catch.

Table 1. Available catch data based on GAFRD statistical book 2021 [8].

Family/Species	Total Catch (ton)	% of the Catch	By Area (ton)
			Gulf of Suez	Gulf of Aqaba	Proper Red Sea
Lethrinidae	2652	5.86
Lethrinus nebulosus	1914		205	14	1695
L. borbonicus	401		184	--	217
L. luntjan	--		--	--	--
L. mahsena	260		15	12	233
L. variegatus	77		77	--	--
L. microdon	--		--	--	--
L. miniata	--		--	--	--
Monotaxis grandoculis	--		--	--	--
Serranidae	3579	7.91
Mix	2379		144	12	2223
Epinephelus summana	--		--	--	--
E. tauvina	31		7	6	18
E. chlorostigma	--		--	--	--
E. areolatus	87		87	--	--
Cephalopholis argus	--		--	--	--
C. oligostikta	--		--	--	--
C. miniata	--		--	--	--
Plectropomus maculatus	844		--	--	844
Variola louti	236		--	6	230
Plectropomus areolatus	2		2	--	--
Lutjanidae	777	1.72
Lutjanus bohar	728	--	1	--	727
L. ehrenbergii	3	--	3	--	--
L. quinquelineatus	--	--	--	--	--
L. kasmira	--	--	--	--	--
Aphareus rutilans	46	--	--	--	46
Haemulidae	383	0.85	--	--	--
Pomadasys argenteus	34	--	--	--	34
P. stridens	315	--	211	--	104
Plectorhinchus shotaf	34	--	--	--	34
Synodontidae	2177	4.81	1417	--	760
Saurida undosquamis
S. tumbil
Mullidae	628	1.39	228	--	400
Mulloidichthys vanicolensis	--	--	--	--	--
M. flavolineatus	--	--	--	--	--
Upeneus vittatus	--	--	--	--	--
U. sulphureus	--	--	--	--	--
U. moluccensis	--	--	--	--	--
U. pori	--	--	--	--	--
Parupeneus forsskali	17	--	2	--	15
P. macronema	--	--	--	--	--
P. cyclostomus	--	--	--	--	--
Holocentridae	78	0.17	15	--	63
Sargocentron rubrum
S. spiniferum
Neoniphon sammara
Carangidae	10,930	24.16
Mix	8545		4984	--	3561
Trachurus indicus	--
Decapterus macrosoma	--
D. maruadsi	--
Alepes djedaba	--
Carangoides bajad	2385		5	--	2380
Nemipteridae	1321	2.92	373	--	948
Nemipterus japonicas
N. zysron
N. randalli
Sparidae	334	0.73
Rhabdosargus haffara	--
Acanthopagrus bifasciatus	--
Argyrops spinifer	310		90	2	218
Diplodus nokt	24		24	--	--
Gerridae	132	0.29	20	3	109
Gerres oyena
Scaridae	980	2.17	165	9	806
Hipposcarus harid
Chlorurs sordidus
Siganidae	377	0.83
Siganus rivulatus	377		164	--	213
Scombridae	3009	6.65
Scomber japonicas	73		73	--	--
Rastrelliger kanagurta	2369		150	--	2219
Euthynnus affinis	567		66	--	501
Clupeidae	10,641	23.52
Sardinella aurita	8297		44	--	8253
Etrumeus teres	1120		1120	--	--
Small sardine *	1224		1224	--	--
Engraulidae	4000	8.84	4000	--
Penaeidae	266	0.59	159	--	107
P. semisulcatus				--
P. japonicas				--
Sepiidae	111	0.45	102	--	9
Sepia pharaoni	--
S. prashadi	--
S. dollfusi	--
Portunidae	188	0.41	156		32
Portunus pelagicus
Loliginidae	507	1.12
Loligo spp.			140	--	367

* Small sardine composed of small-sized sardines such as Dussumieria acuta, Amblygaster sirm, Amblygaster clupeoides, Ilisha melastoma, and Herklosichthys punctatus (personal observation). -- indicates an absence of data in the national recording system.

presents catch data from the GAFRD’s 2021 statistical book. It is worth mentioning that the data recording system in Egypt is inaccurate. Many commercial species are not recorded separately but mixed in an “others” group. Also, there is no recorded data about bycatch and discards in the Egyptian marine fisheries. Therefore, urgent improvements are needed for the current recording system, as well as capacity-building programs to raise the qualifications of recorders at the different landing sites.

The field trips revealed a high diversity and abundance of fish species, especially in the Gulf of Aqaba, which the current catch statistics may not fully capture. Additionally, catch data are often recorded for groups of species rather than individual species.

The trawl fishery primarily catches fish from groups such as Synodontidae (lizardfish), Lutjanidae (snapper), Penaeidae (large shrimp), Mullidae (red mullet), Nemipteridae (breams), and Siganidae (rabbitfish). It is worth noting that large shrimp and cuttlefish are the most commercially valuable species in the trawl fishery, commanding high prices between EGP 300 and 500 per kilogram and representing about 45% of the trawl fishery’s gross revenue.

While the dominant fish families in the artisanal catch include groupers (Serranidae), emperors (Lethrinidae), and longspine bream (Sparidae), other Scombridae (little tuna and Spanish mackerel) are also present. More than 100 fish species from up to 20 families, like needlefish, squirrelfish, goatfish, and rabbitfish, were grouped together in the “others” category without any sorting or identification [1,13,14]. This “others” group constitutes about 46.5 percent of the total artisanal landings, highlighting the lack of accuracy and detail in the current fishery statistics collection and recording system.

Unlike the Gulf of Suez, where industrial fisheries dominate, artisanal fishing is the primary activity in the proper Red Sea and Gulf of Aqaba. It supplies approximately 40% of the total fish production from the proper Red Sea and constitutes the total of the Gulf of Aqaba’s catch [8,13,14,15,16,17,18,19].

3.2. Population Parameters and Exploitation Level

As shown in

Table 2. Growth parameters and mortality estimates of fish species from Red Sea, Egypt.

Species	Area	Author	Parameters
			L∞	K	F	M	E
Lethrinus nebulosus	Gulf of Suez	Present study	71.4	0.24	0.55	0.29	0.65
	Hurghada	Present study	73.6	0.22	0.61	0.29	0.68
L. borbonicus	Gulf of Suez	Present study	32.5	0.42	0.81	0.45	0.64
	Aqaba Gulf	Mehanna, 2023 [17]	35.8	0.48	0.70	0.72	0.49	opt
	Shalateen	Mehanna, 2011 [16]	34.57	0.53	1.65	0.62	0.73
L. luntjan	Red Sea	Zaahkouk et al., 2017 [23]	56.95	0.28	1.17	0.35	0.77
L. mahsena	Gulf of Suez	Present study	61.8	0.29	1.05	0.33	0.76
L. variegatus	Aqaba Gulf	Mehanna et al., 2024 [23]	25.79	0.51	0.80	1.01	0.44	opt
	Hurghada	Present study	26.11	0.50	1.11	0.67	0.62
L. microdon	Red Sea	Mehanna et al., 2017 [24]	67.46	0.25	0.74	0.30	0.71
Monotaxis grandoculis	Hurghada	ElMahdy et al., 2022 [25]	53.87	0.23	0.46	0.52	0.47	opt
Epinephelus summana	Hurghada	Mehanna et al., 2022 [26]	63.39	0.13	0.49	0.33	0.60
E. areolatus	Shalateen	Mehanna, 2005 [27]	48.79	0.31	0.55	0.13	0.81
E. tauvina	Hurghada	Present study	106.3	0.11	0.79	0.22	0.78
Cephalopholis argus	Hurghada	Mehanna et al., 2019 [26]	44.22	0.26	0.74	0.56	0.57
C. miniata	Quseir	Mohammad, 2007 [28]	39.99	0.23	1.26	0.58	0.68
Variola louti	Quseir	Mohammad, 2007 [28]	62.57	0.14	0.63	0.37	0.63
L. ehrenbergii	Hurghada	Mehanna et al., 2017 [29]	32.4	0.47	1.48	0.69	0.68
L. quinquelineatus	Hurghada	Mehanna et al., 2017 [29]	35.5	0.35	1.38	0.61	0.69
L. kasmira	Shalateen	Baker&Mehanna, 2024 [30]	33.76	0.35	0.99	0.59	0.62
P. stridens	Gulf of Suez	Mehanna et al., 2023 [31]	21.7	0.40	1.76	0.74	0.70
Saurida undosquamis	Baraneis	Mehanna, 2022 [32]	48.66	0.33	1.28	0.45	0.74
S. tumbil	Baraneis	Mehanna, 2022 [32]	35.30	0.43	1.19	0.46	0.72
Mulloidichthys vanicolensis	Hurghada	Farrag et al., 2018 [33]	33.30	0.37	0.79	0.64	0.56
M. flavolineatus	Hurghada	Farrag et al., 2018 [33]	38.0	0.27	1.01	0.48	0.68
Upeneus moluccensis	Gulf of Suez	Present study	22.99	0.38	1.06	0.48	0.69
U. pori	Gulf of Suez	Present study	20.85	0.40	0.85	0.44	0.66
Parupeneus forsskali	Hurghada	Farrag et al., 2018 [33]	31.62	0.32	0.54	0.55	0.49	opt
Sargocentron spiniferum	Shalateen	Mohammad et al., 2020 [19]	53.25	0.23	0.57	0.47	0.55
Neoniphon sammara	Hurghada	ElMahdy et al., 2023 [34]	26.49	0.28	0.82	0.57	0.59
Trachurus indicus	Gulf of Suez	Present study	24.81	0.51	0.91	0.36	0.72
Decapterus macrosoma	Gulf of Suez	Present study	25.11	0.56	0.90	0.32	0.74
D. maruadsi	Gulf of Suez	Present study	26.21	0.51	1.06	0.56	0.65
Carangoides bajad	Shalateen	Mohammad et al., 2022 [35]	57.69	0.24	1.52	0.34	0.82
Caranx melampygus	Shalateen	Mohammad et al., 2022 [35]	70.11	0.17	1.75	0.28	0.86
Alepes djedaba	Hurghada	Present study	41.12	0.41	1.21	0.46	0.72
Nemipterus japonicas	Gulf of Suez	Present study	34.15	0.33	1.18	0.56	0.68
N. zysron	Aqaba Gulf	Present study	29.31	0.51	0.90	0.62	0.59
N. randalli	Hurghada	Present study	28.11	0.54	1.38	0.66	0.68
Rhabdosargus haffara	Gulf of Suez	Mehanna, 2001 [20]	26.79	0.47	0.90	0.30	0.76
	Hurghada	Osman et al., 2020 [22]	30.47	0.36	1.32	0.66	0.67
Acanthopagrus bifasciatus	Hurghada	ElMahdy et al., 2019 [36]	65.62	0.21	1.53	0.46	0.77
Gerres oyena	Gulf of Suez	Present study	26.11	0.38	0.81	0.44	0.65
Hipposcarus harid	Hurghada	Osman, 2015 [37]	57.16	0.23	1.75	0.50	0.78
Chlorurs sordidus	Hurghada	Osman, 2015 [37]	40.27	0.28	0.82	0.60	0.58
Siganus rivulatus	Gulf of Suez	Present study	25.31	0.44	1.72	0.67	0.72
	Shalateen	Present study	36.44	0.36	1.02	0.37	0.73
Scomber japonicas	Gulf of Suez	Mehanna, 2002 [38]	33.06	0.48	1.82	0.64	0.74
Rastrelliger kanagurta	Gulf of Suez	Mehanna, 2001 [21]	32.15	0.57	0.82	0.26	0.76
Euthynnus affinis	Aqaba Gulf	Mehanna, 2024 [18]	83.64	0.47	0.65	0.77	0.46	opt
Sardinella aurita	Gulf of Suez	Present study	23.33	0.48	1.05	0.27	0.79
S. gibbosa	Gulf of Suez	Present study	33.15	0.47	0.89	0.57	0.60
Etrumeus teres	Red Sea	Mehanna and Elgammal (2005) [39]	26.97	0.59	1.46	0.87	0.63
Engraulis japonicas	Gulf of Suez	Present study	15.45	0.61	0.71	0.34	0.68
E. encrasicolus	Gulf of Suez	Present study	12.61	0.55	1.49	1.02	0.59
Penaeus semisulcatus	Gulf of Suez	Mehanna, 2000 [40]	26.61	1.69	5.45	2.33	0.70
P. japonicas	Gulf of Suez	Present study	24.3	1.71	4.73	2.45	0.66
Sepia pharaoni	Gulf of Suez	Mehanna et al., 2009 [15]	23.48 ML	0.59	2.11	0.77	0.73
S. savignyi	Gulf of Suez	Mehanna and Elgammal (2010) [41]	31.29 ML	0.54	0.89	0.57	0.60
S. dollfusi	Gulf of Suez	Mehanna and Amin (2005) [42]	16.9 ML	0.91	2.50	1.07	0.70
Portunus pelagicus	Gulf of Suez	Present study	10.96 CL	1.44	6.56	2.11	0.76

ML: Mantle Length, CL: Carapace Length.

, the population parameters and status of 55 fish, crustacean, and mollusk species from the Egyptian Red Sea are presented. Despite the fact that both of Mehanna’s (2001) [20,21] studies might be outdated, they are included in Table 2 to capture all the available data. Mehanna’s (2001) [20] study is the only one that has assessed Rhabdosargus haffara in the Gulf of Suez, although Osman et al. (2020) [22] more recently evaluated the same species in the Red Sea off the Hurghada fishing area. Similarly, Mehanna’s (2001) [21] study remains the sole one on Rastrelliger kanagurta in the Gulf of Suez. Based on Gulland’s (1971) interpretation of the exploitation level, only five fish species are maintained at below slightly optimum exploitation levels: Lethrinus borbonicus, L. variegatus, and Euthynnus affinis from the Gulf of Aqaba and Monotaxis grandoculis and Parupeneus forsskali from Hurghada in the proper Red Sea. The remaining species, 50 out of the 55 assessed commercial species (90.9%), were found to be overexploited.

4. Conclusions

Our analysis of the Egyptian Red Sea’s most commercially important fish species reveals a high fishing mortality, which indicates a high exploitation level. Therefore, a reduction in exploitation rate and consequently the fishing mortality by about 20 to 70% is suggested to reach the optimum level (E_opt), which would help ensure the sustainability of the fish stocks. This can be achieved through enforcement of the closed fishing season and enforcement of the minimum legal size to conserve the spawning stock. The basic biological information generated from this study will be valuable for further population studies and stock assessment. These findings, in turn, can be applied to develop sustainable management measures for these commercially exploited fish species.